Polyimides, process for the preparation thereof and polyimide resin compositions

ABSTRACT

In one aspect, the present invention relates to polyimides having excellent thermal resistance and process for preparing the same comprising carrying out condensation of 4,4&#39;-bis(3-aminophenoxy)biphenyl with pyromellitic dianhydride in the presence of a different diamine compound and optionally with a different tetracarboxylic acid dianhydride. 
     In a second aspect, the present invention relates to a heat resistant resin composition consisting essentially of an aromatic polyetherimide and a defined polyimide. 
     In a third aspect, the present invention relates to a polyimide resin composition comprised on a defined polyimide and a separate high-temperature engineering polymer. 
     In a fourth aspect, the present invention relates to a resin composition comprised of a defined polyimide and an aromatic polyamideimide.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of allowed application Ser. No.07/608,727, filed Nov. 5, 1990, now U.S. Pat. No. 5,288,843 which is acontinuation-in-part of application Ser. No. 196,492, filed on May 20,1988, application Ser. No. 199,918, filed on May 27, 1988, applicationSer. No. 202,031, filed on Jun. 3, 1988, and application Ser. No.551,314 filed Jul. 12, 1990 which is a continuation of application Ser.No. 426,715, filed on Oct. 26, 1989, all of these latter applicationsnow being abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

In one aspect, the present invention relates to polyimides that exhibitexcellent thermal resistance and processability, and to a process forpreparing the polyimides. In this aspect, the invention relates to aprocess for preparing crystalline polyimides by controlling the rate ofcrystallization without varying the substantial crystallinity of thepolyimides, to a process for preparing non-crystalline polyimides havingoutstanding processability and thermal resistance, and to the polyimidesprepared by these processes.

In other aspects, the invention relates to polyimide resin compositionshaving advantageous properties, such as heat and chemical resistance,mechanical strength and moldability.

2. Description of the Related Art

Polyimides prepared by reacting tetracarboxylic dianhydride and adiamine compound exhibit excellent mechanical strength, dimensionalstability, high thermal resistance, flame retardance and electricalinsulation properties. Hence polyimides have conventionally been used invarious fields such as electrical and electronic instruments, aerospaceand aircraft equipment, and transport machinery. These types ofpolyimides are expected to be useful in applications in which thermalresistance is required. Thus, various types of polyimides having theabove characteristics have been developed.

Some of the polyimides, however, do not exhibit definite glasstransition temperatures, although they exhibit excellent heatresistance, and hence must be processed by such means as sinter moldingto be useful for molding purposes. Other polyimides have low glasstransition temperatures and are soluble in halogenated hydrocarbons,although they exhibit excellent processability, and hence areunsatisfactory in view of their thermal and solvent resistances.

In order to obtain polyimides having the above desired properties,crystalline polyimides have also been developed. For example, polyimidesderived from 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydrideand p-phenylenediamine have a crystal structure (T. L. St. Clair et al,J. Polym. Sci., Polym. Chem. ed. 1977, vol. 15, No. 6, p. 1529) as dopolyimides derived from 3,3',4,4'-benzophenonetetracarboxylicdianhydride and 1,3-bis[4'-(3-aminophenoxy)benzoyl]benzene, which have asemi-crystalline structure (P. M. Hergenrother et al, SAMPE Journal,July/August 1988, p. 13).

Although the above crystalline polyimides exhibit superior thermalresistance as compared to non-crystalline polyimides, their crystallinestructure causes difficulty in processing and thus their applicationsare limited.

No process has previously been known which can improve theprocessability of crystalline polyimides without impairing theiressential property, i.e., thermal resistance.

It has previously been found that polyimides obtained by condensation of4,4'-bis(3-aminophenoxy)biphenyl with pyromellitic dianhydride,containing recurring structural units represented by the formula (VI):##STR1## have a glass transition temperature (hereinafter referred to asTg) of 260° C., a crystallization temperature (hereinafter referred toas Tc) of from 310° to 340° C. and a crystalline melting point(hereinafter referred to as Tm) of from 367° to 390° C., and that suchpolyimides are crystalline polyimides that can be melt-processed andexhibit excellent chemical resistance [Japanese patent Laid-Open No.62-205124 (U.S. Pat. No. 4,847,349)].

The polyimide has a much higher Tg of 260° C. as compared with a Tg of140° C. of polyetherether ketone (Trade Mark; VICTREX PEEK, a product ofICI), a crystalline engineering plastic and a Tg of 225° C. of aromaticpolysulfone (Trade Mark; VICTREX PES, a product of ICI), anon-crystalline engineering plastic. Consequently, the above polyimideis an excellent engineering plastic material in view of its thermalresistance.

The above polyimide, however, has a high Tm of from 367° to 390° C. andmust be molded at a high temperature of about 400° C., which temperaturecauses processing problems. Further improvement of processability hasbeen required for the above polyimide.

When a crystalline resin and a non-crystalline resin having the samelevel of glass transition temperature are compared in view ofengineering plastics having high thermal resistance, the crystallineresin is generally excellent in chemical resistance and mechanicalproperties such as elastic modulus whereas the non-crystalline resin isoutstanding in processability. Thus, crystalline resins andnon-crystalline resins, respectively, have both advantages anddrawbacks.

In consideration of the above circumstances, engineering plastics havinggood processability, excellent chemical resistance, high elastic modulusand good thermal resistance can be obtained, when the substantiallyexcellent thermal resistance of crystalline polyimides consisting ofrecurring structural units represented by the above formula (VI) ismaintained and processability is improved; for example, whenprocessability is improved under the non-crystalline state in theprocessing step and polyimides having excellent thermal resistance canbe subsequently obtained by converting to the crystalline state afterprocessing. The same effect can also be obtained, when processability isimproved by holding the non-crystalline state during and afterprocessing step and the non-crystalline polyimide thus obtained has highthermal resistance.

It is expected that an essentially crystalline polymer would improveprocessability and to extend utilization to various fields ofapplications if a method is developed for freely controlling thecrystallization rate of the polymer.

Investigations on the rate of crystallization and the method forcontrolling the rate have never been carried out on the crystallinepolyimide.

Other polyimides also have been difficult to process or have otherdisadvantages. For example, polyimide consisting of a polymer chainrepresented by the following formula: ##STR2## (Trade Mark; KAPTON andVESPEL, products of E. I. du Pont de Nemours and Co.) indicates nodistinct glass transition temperature and has an excellent heatresistance. The polyimide, however, is difficult to process by hotmolding.

An aromatic polyetherimide (Trade Mark; ULTEM, a product of GeneralElectric Co.) has been known to be capable of improving theprocessability of conventional polyimide. The typical aromaticpolyetherimide is represented by the following formula: ##STR3## Inspite of imide linkages in the molecule similar to conventionalpolyimide, the polyetherimide can be fusion molded and is excellent inmechanical strength, flame retardance, electrical property and moldingability, thereby having a wide field of use. Said aromaticpolyetherimide, however, has a low heat distortion temperature of about200° C. as compared with that of conventional polyimide of 280° C.Accordingly, reduction of mechanical and abrasion properties at hightemperatures has caused problems on the development of its application.In order to improve these disadvantages solid lubricants such asgraphite, fluororesin, titanium oxide and molybdenum disulfide are addedto the aromatic polyetherimide in combination with or separately frominorganic fillers such as glass fibers and carbon fibers. However, theaddition of inorganic fillers leads to lower abrasion resistance andthat of solid lubricants tends to cause a marked reduction in mechanicalstrength.

A method for the simultaneous use of aromatic polyetherimide and anotherresin such as aromatic polyamideimide has also been developed. Even insuch a case, however, retention of mechanical strength, particularlyimpact and abrasion resistances has been still unsatisfactory.

Other polyimides have a repeating unit represented by the formula:##STR4## where X indicates a direct bond or is a radical selected fromthe group consisting of divalent hydrocarbon radicals having carbonatoms of 1 to 10, isopropylidene hexafluoride radical, carbonyl, thio,and sulfonyl, and R is a tetravalent radical selected from the groupconsisting of aliphatic radicals having at least 2 carbon atoms,alicyclic radicals, monocyclic aromatic radicals and fused polycyclicaromatic radicals, and polycyclic aromatic radicals including aromaticradicals interconnected directly or through a cross-linkage as forexample, disclosed in Japanese Laid-Open Patent Nos. 143478/1986,68817/1987, 86021/1987, and 50372/1987, and in Japanese PatentApplication Nos. 076475/1986 and 274206/1986.

Within this definition can be obtained a thermoplastic polyimide havingfluidity at high temperatures in addition to excellent mechanical,thermal and electrical properties which are substantial in polyimide.Compared to ordinary engineering polymers represented by polyethyleneterephthalate, polybutylene terephthalate, polysulfone and polyphenylenesulfide, the polyimide is much superior in high-temperature resistanceand other properties. On the other hand, the processing ability of thepolyimide is still inferior to these polymers.

Further polyimides having excellent mechanical, thermal, electricalcharacteristics and solvent resistance and having heat resistance, havea repeating unit represented by the formula: ##STR5## where R is atetravalent radical selected from the group consisting of aliphaticradicals having at least 2 carbon atoms, alicyclic radicals, monocyclicaromatic radicals and fused polycyclic aromatic radicals, and polycyclicaromatic radicals including aromatic radicals interconnected directly orthrough a cross-linkage (for example, Japanese Laid-Open Patent No.50372/1987).

On the other hand, in the electronic field, there is required higherheat resistance with increasing integration in appliances andinstruments.

Also, the aerospace material industry requires reduction in weight andimproved strength of aircrafts with higher speed and larger amounts oftransportation, reflecting the requirement for materials having highheat resistance and good strength compared with conventionalthermoplastic resins.

SUMMARY OF THE INVENTION

Among its various aspects, the present invention overcomes the problemsand disadvantages of the prior art by providing polyimides that exhibitexcellent thermal resistance and processability.

It is an object of a first aspect of the invention to provide apolyimide having high thermal resistance and excellent processability.

It is a further object of the first aspect of the invention to provide anon-crystalline polyimide having excellent processability and high heatresistance.

It is an additional object of the first aspect of the invention toprovide a process for preparing a crystalline polyimide by favorably andfreely controlling the rate of crystallization in the processing ofpolyimide as a means for utilizing the essential high heat resistancewhile improving processability of the above crystalline polyimide.

It is an object of a second aspect of the invention to provide a heatresistant resin composition having mechanical strength, particularlyimpact and abrasion resistances at high temperatures, while maintainingexcellent properties such as flame retardance, electrical properties,mechanical strength and moldability which are essential characteristicsof aromatic polyetherimide.

It is an object of a third aspect of the invention to provide a moldingresin composition containing polyimide which has a very excellent meltflowability without adverse effects on the essential properties of thepolyimide.

It is an object of a fourth aspect of the invention to provide apolyimide resin composition having improved heat resistance and/ormechanical strength in addition to its intrinsic favorable properties.

Additional objects and advantages of the various aspects of theinvention will be set forth in part in the description which follows,and in part will be obvious from the description, or may be learned bypractice of the invention. The objects and advantages of the inventionwill be realized and attained by means of the instrumentalities andcombinations, particularly pointed out in the appended claims.

To achieve the objects in accordance with the purpose of the invention,as embodied and broadly described herein, a first aspect of theinvention provides a process for preparing a polyimide comprisingcarrying out condensation of 4,4'-bis(3-aminophenoxy)biphenyl of theformula (I): ##STR6## with a pyromellitic dianhydride of the formula(II): ##STR7## in the presence of at least one diamine compound selectedfrom a defined list and optionally with a further tetracarboxylic aciddianhydride represented by the formula (IV) ##STR8## wherein R₂ is atetravalent group selected from the group consisting of an aliphaticgroup, an alicyclic group, a monocyclic aromatic group, a fusedpolycyclic aromatic group and a polycyclic aromatic group combined witha direct bond or via a bridge member.

Applicants have found that the essentially crystalline polyimide can beobtained in the form of noncrystalline polyimide by the process of thefirst aspect of the invention.

By the process of the first aspect of the invention, the rate ofcrystallization can be controlled, and processability can be improvedwithout impairing the essential thermal resistance of the polyimide andwithout an adverse effect on the essential characteristics of thepolyimide.

The polyimides prepared by the process of the first aspect of theinvention exhibit excellent thermal resistance and processability andare useful in numerous applications such as molded articles and heatresistant films.

The accompanying drawings, which are incorporated in and constitute apart of this application, illustrate several exemplary embodiments ofthe first aspect of the invention and together with the description,serve to explain the principles of this aspect of the invention.

In a second aspect, the present invention relates to a resin compositionconsisting essentially of 95-5 wt. % of aromatic polyetherimide and 5-95wt. % of a polyimide composed of recurring units represented by theformula ##STR9## wherein X is a direct bond or --S--, and Y is atetravalent group selected from the group consisting of an aliphaticgroup having at least two carbon atoms, alicyclic group, a monocyclicaromatic group, a fused polycyclic aromatic group and a polycyclicaromatic group where aromatic groups are connected to each other with adirect bond or via a bridge member.

In a third aspect, the present invention relates to a polyimide resincomposition comprised of 99.9 to 50% by weight of polyimide which hasrecurring units of the formula: ##STR10## wherein Z is a direct bond,thio radical or a phenylene dicarbonyl radical where two carbonylradicals are meta or para located on the benzene ring and Y is atetravalent group selected from the group consisting of an aliphaticgroup having at least 2 carbon atoms, an alicyclic group, a monocyclicaromatic group, a fused polycyclic aromatic group and a polycyclicaromatic group where aromatic groups are linked to one another directlyor via a bridge member, and 0.1 to 50% by weight of high-temperatureengineering polymer selected from the group consisting of polyphenylenesulfide, aromatic polysulfone and aromatic polyetherimide, and wheresaid high temperature engineering polymer is polyphenylene sulfide oraromatic polysulfone when Z is the direct bond or thio radical.

In a fourth aspect, the present invention provides a resin compositionwhich comprises 99.9 to 50% by weight of a polyimide having a recurringunit represented by the general formula: ##STR11## wherein Z is a directbond or is ##STR12## and Y is a tetravalent group selected from thegroup consisting of an aliphatic group having at least 2 carbon atoms,an alicyclic group, a monocyclic aromatic group, a fused polycyclicaromatic group, and a polycyclic aromatic group where the aromaticgroups are connected directly or via a bridge member and 0.1 to 50% byweight of an aromatic polyamide imide.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the relationship of crystallinity with time in a Geeroven at 300° C. in Example 9, 10 and Comparative Example 4.

FIG. 2 illustrates the relationship of crystallinity with time in a Geeroven at 300° C. in Examples 9, 11-13 and Comparative Example 4.

FIG. 3 illustrates the molding stability of the polyimide obtained inExample 15 and Example 20.

The molding stability was compared by changing the dwell time of thepolyimide in the cylinder of a flow tester at a cylinder temperature of420° C. and under a pressure of 100 kg/cm².

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the various aspects of the invention.

In the process of the first aspect of the invention, the diaminecompound and the tetracarboxylic acid dianhydride are preferablyemployed in an amount of from about 1 to about 100% by mole of4,4'-bis(3-aminophenoxy)biphenyl and/or pyromellitic dianhydride. Morepreferably, the diamine compound and/or tetracarboxylic acid dianhydrideare each employed in an amount of from about 1 to about 30% by mole. Insuch amounts, the rate of crystallization can be reduced to a desiredlevel corresponding to the amount used and a crystalline polyimide canstill be obtained. The polyimide powder thus obtained has improvedprocessability due to its non-crystalline structure and can also beconverted to a crystalline structure in the processing step to providemolded articles of polyimide having excellent thermal resistance.

When employed in an amount of from about 30 to about 100% by mole, thecrystallization rate becomes extremely slow and a polyimide ofsubstantially crystalline structure cannot be formed under typicalprocessing conditions. Consequently, the resulting polyimide has anon-crystalline structure.

The non-crystalline polyimide thus obtained has improved processabilityand almost no loss is found in the high thermal resistance which is anessential characteristic of crystalline polyimide.

Suitable diamine compounds used to prepare the polyimides of this aspectof the invention include the compounds of the formula (III):

    H.sub.2 N-R.sub.1 -NH.sub.2

wherein R₁ is a divalent group selected from the group consisting of analiphatic group, an alicyclic group, a monocyclic aromatic group, afused polycyclic aromatic group and polycyclic aromatic group combinedwith a member selected from the group consisting of a direct bond and abridge member and said diamine compound is selected from at least one ofm-aminobenzylamine and p-aminobenzylamine and ethylenediamine;1,4-diaminocyclohexane; m-phenylenediamine, o-phenylenediamine andp-phenylenediamine; diaminonaphthalenes such as 2,6-diaminonaphthalene;4,4'-diaminobiphenyl; 3,4'-diaminobiphenyl and 3,3'-diaminobiphenyl; andbis(3-aminophenyl) ether, (3-aminophenyl) (4-aminophenyl) ether,bis(3-aminophenyl) sulfide, (3-aminophenyl)(4-aminophenyl) sulfide,bis(4-aminophenyl) sulfide, bis(3-aminophenyl) sulfoxide,(3-aminophenyl)(4-aminophenyl) sulfoxide, bis(4-aminophenyl) sulfoxide,bis (3-aminophenyl) sulfone, (3-aminophenyl)(4-aminophenyl) sulfone,bis(4-aminophenyl) sulfone, 3,3'-diaminobenzophenone,3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone,3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane,4,4'-diaminodiphenylmethane, bis[4-(4-aminophenoxy)phenyl]methane,1,1-bis[4-(4-aminophenoxy)phenyl]ethane,1,2-bis[4-(4-aminophenoxy)phenyl]ethane,2,2-bis[4-(4-aminophenoxy)phenyl]propane,2,2-bis[4-(4-aminophenoxy)phenyl]butane,2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane,1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene,1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene,bis[4-(4-aminophenoxy)phenyl]ketone,bis[4-(4-aminophenoxy)phenyl]sulfide,bis[4-(4-aminophenoxy)phenyl]sulfoxide,bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenylether,1,4-bis[4-(3-aminophenoxy)benzoyl]benzene,1,3-bis[4-(3-aminophenoxy)benzoyl]benzene,4,4'-bis[3-(4-aminophenoxy)benzoyl]diphenyl ether,4,4'-bis[3-(3-aminophenoxy)benzoyl]diphenyl ether,4,4'bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone, 4,4'bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenyl sulfone andbis[4-(4-(4-aminophenoxy)phenoxy)phenyl]sulfone. The above compounds maybe used singly or in combination. It will be noted that the diaminecompound used in this aspect of the invention does not include4,4'-bis(3-aminophenoxy)biphenyl.

The diamine compounds may be also at least one diamine compound selectedfrom the group consisting of: ##STR13## wherein X₁ is a direct bond, O,CO, SO₂, SO, S, or CH₂ with the proviso that the diamine compound is not4,4'diaminodiphenyl ether ##STR14## wherein X₂ is a direct bond, CO,SO₂, SO, S, ##STR15## wherein n is 1-4, and ##STR16## wherein X₂ isdefined above.

Among the above diamine compounds exemplary preferred compounds includem-phenylenediamine, p-phenylenediamine, bis(3-aminophenyl) ether,(3-aminophenyl)(4-aminophenyl) ether, 1,3-bis(3-aminophenoxy)benzene,1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene and1,4-bis(4-aminophenoxy)benzene.

Exemplary suitable tetracarboxylic acid dianhydrides of the formula (IV)which may be used to prepare the polyimides of this aspect of theinvention include dianhydrides wherein R₂ is an aliphatic group, such asethylenetetracarboxylic dianhydride and butanetetracarboxylicdianhydride; dianhydrides wherein R₂ is an alicyclic group, such ascyclopentanetetracarboxylic dianhydride; dianhydrides wherein R₂ is amonocyclic aromatic group, such as 1,2,3,4-benzenetetracarboxylicdianhydride; dianhydrides wherein R₂ is a fused polycyclic aromaticgroup, such as 2,3,6,7-naphthalenetetracarboxylic dianhydride,1,4,5,8-naphthalenetetracarboxylic dianhydride,1,2,5,6-naphthalenetetracarboxylic dianhydride,3,4,9,10-perylenetetracarboxylic dianhydride,2,3,6,7-anthracenetetracarboxylic dianhydride, and1,2,7,8-phenanthrenetetracarboxylic dianhydride; dianhydrides wherein R₂is a polycyclic aromatic group combined with a direct bond, such as3,3'4,4'-biphenyltetracarboxylic dianhydride and2,2'3,3'-biphenyltetracarboxylic dianhydride; and dianhydrides whereinR₂ is a polycyclic aromatic group combined via a bridge member, such as3,3',4,4'-benzophenonetetracarboxylic dianhydride,2,2',3,3'-benzophenonetetracarboxylic dianhydride,2,2'-bis(3,4-dicarboxyphenyl)propane dianhydride,bis(3,4-dicarboxyphenyl) ether dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl) sulfone dianhydride,bis(2,3-dicarboxyphenyl) sulfone dianhydride,2,2-bis(3,4-dicarboxyphenyl)1,1,1,3,3,3-hexafluoropropane dianhydride,2,2-bis(3,4-dicarboxyphenyl)1,1,1, 3,3,3-hexachloropropane dianhydride,1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride,bis(2,3-dicarboxyphenyl)methane dianhydride,bis(3,4-dicarboxyphenyl)methane dianhydride,4,4'-(p-phenylenedioxy)diphthalic dianhydride and4,4'-(m-phenylenedioxy)diphthalic dianhydride. The dianhydride compoundmay be used singly or in combination. Numerous tetracarboxylic aciddianhydrides may be used except pyromellitic dianhydride.

Among the above tetracarboxylic acid dianhydrides of the formula (IV),the compounds wherein R₂ is a polycyclic aromatic group combined with adirect bond or via a bridge member are preferably used. Exemplarypreferred compounds include 3,3'4,4'-benzophenonetetracarboxylicdianhydride, 3,3'4,4'-biphenyltetracarboxylic dianhydride,bis(3,4-dicarboxyphenyl)ether dianhydride and4,4'-(p-phenylenedioxy)diphthalic dianhydride. More preferably,3,3'4,4'-biphenyltetracarboxylic dianhydride is employed.

The diamine compound and optionally the tetracarboxylic acid dianhydrideof the formula (IV) are incorporated into the reaction system asauxiliary materials in the process of the first aspect of thisinvention. Reaction of the main materials in the presence of theseauxiliary materials forms several kinds of imide units which are derivedfrom the diamine ingredient containing 4,4'-bis(3-aminophenoxy)biphenyland the diamine compound and the dianhydride ingredient containingpyromellitic dianhydride and the tetracarboxylic acid dianhydride of theformula (IV). These new types of units are thought to cut in the chainof essential recurring structural units of the formula (VI) derived fromthe main materials, i.e., 4,4'-bis(3-aminophenoxy)biphenyl andpyromellitic dianhydride, and to form a complex polymer chain ofpolyimide.

It is difficult to identify the structure of these polyimide linkages.In practice, however, crystalline polyimide or non-crystalline polyimidecan be obtained by adjusting the amounts of the diamine compound and/ortetracarboxylic acid dianhydride for auxiliary use in theabove-mentioned range.

The diamine compound and the tetracarboxylic acid dianhydriderepresented by the formula (IV) may be used singly or as a mixture in asuitable proportion.

Preferably the diamine compound and tetracarboxylic acid dianhydride ofthe formula (IV) is employed in an amount of from about 1 to about 100%by mole of the main monomer, i.e., 4,4'-bis(3-aminophenoxy)biphenyland/or pyromellitic dianhydride. Use in an amount less than about 1% bymole leads to a rapid rate of crystallization of the polyimide composedof the recurring structural units represented by the formula (VI). Theresulting polyimide is rapidly converted to a crystalline polyimide andis unfavorable for improving processability. On the other hand, use inan amount exceeding 100% by mole results in an adverse effect on theexcellent characteristics of the polyimide. Most preferably, the diaminecompound and the tetracarboxylic acid dianhydride of the formula (IV) isemployed in an amount of from about 5 to about 50% by mole of4,4'-bis(3-aminophenoxy)biphenyl and/or pyromellitic dianhydride.

In the case where a non-crystalline polyimide is prepared from bis(4-aminophenyl)ether as the most preferable diamine compound selectedfrom the formula (III), bis(4-aminophenyl)ether is employed in an amountof from about 2 to about 30% by mole of4,4'-bis(3-aminophenoxy)biphenyl.

A part of the bis(4-amino-phenoxy)ether may be replaced by otherdiamines without adverse effect on the beneficial properties of thepolyimide. Exemplary suitable diamines to be used for the partialreplacement have been set forth above.

A non-crystalline polyimide can be obtained by using the above amount.When used in an amount of about 30% by mole or less, the crystallizationrate can be controlled to a desired level by selecting the treatingconditions and a crystalline polyimide can also be prepared. In the samerange of amount for use, it is also possible to prepare anon-crystalline polyimide and to convert the resultant non-crystallinepolyimide to crystalline polyimide under selected processing conditions.In these cases, the amount of the diamine compound and tetracarboxylicacid dianhydride of the formula (IV) for auxiliary use is about 30% bymole or less, preferably from about 2 to about 30% by mole of the mainmonomer materials, i.e., 4,4'-bis(3-aminophenoxy)biphenyl and/orpyromellitic dianhydride. When an amount exceeding about 30% by mole isemployed, it is difficult to give a substantially crystalline polyimide.The use of an amount in large excess of about 30% by mole can alreadyprovide a non-crystalline polyimide. Consequently, a crystallinepolyimide can be arbitrarily obtained at a certain temperature at adesired rate of crystallization by selecting the amount of auxiliarymonomer in the range of 30% by mole or less of4,4'-bis(3-aminophenoxy)biphenyl and/or pyromellitic dianhydride, whichmeans that processability can be improved and molded products havingexcellent thermal resistance can be simultaneously obtained.

In the process for preparing the polyimide of this invention, polyamicacid is prepared by reacting 4,4'-bis(3-aminophenoxy)biphenyl withpyromellitic dianhydride in the presence of the diamine compound and/ora tetracarboxylic acid dianhydride of the formula (IV).

No particular restriction is imposed on the method of reaction. However,organic solvents are preferably used for the reaction. Exemplarysuitable organic solvents include N,N-dimethylformamide,N,N-dimethylacetamide, N,N-diethylacetamide,N,N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone,1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam,1,2-dimethoxyethanebis(2-methoxyethyl)ether,1,2-bis(2-methoxyethoxy)ethane, bis[2-(2-methoxyethoxy)ethyl]ether,tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, pyridine, picoline, dimethylsulfoxide, dimethyl sulfone, tetramethylurea, hexamethylphosphoramide,phenol, o-cresol, m-cresol, m-cresylic acid, p-cresol, p-chlorophenoland anisol. These organic solvents may be used singly or in combination.

A reaction temperature of about 250° C. or less is preferably employed,more preferably a temperature of about 50° C. or less is employed. Noparticular limitation is placed upon the pressure and the reaction canbe satisfactorily carried out at atmospheric pressure. Reaction time isdifferent depending upon the solvent and reaction temperature. Areaction time of from about 4 to about 24 hours is usually sufficient.

The polyamic acid thus obtained is further imidized by heating at fromabout 100° to about 400° C. or chemically imidized with an imidizingagent such as acetic anhydride, to obtain a polyimide having recurringunits corresponding to the polyamic acid.

Alternatively, 4,4'-bis(3-aminophenoxy)biphenyl and pyromelliticdianhydride may be suspended or dissolved in an organic solvent togetherwith the diamine compound and optionally the tetracarboxylic aciddianhydride of the above formula (IV). Then, the resulting mixture isheated to carry out formation of a polyamic acid precursor andsimultaneous imidization. The polyimide can thus be prepared.

The above reactions are in some cases carried out in the presence ofphthalic anhydride.

Preferably, phthalic anhydride is employed in an amount of from about0.001 to about 1.0 mole per mole of the total diamine compounds used asthe main and auxiliary materials. If employed in an amount less thanabout 0,001 mole, the phthalic anhydride does not provide thermalresistance of the polyimide at high temperatures, whereas an amountexceeding 1.0 mole lowers the mechanical strengths of the polyimide.Most preferably, the phthalic anhydride is employed in an amount of fromabout 0.001 to about 0.5 mole.

The reaction in the presence of phthalic anhydride may be carried out byany of the following methods.

(A) Reacting pyromellitic dianhydride with4,4'-bis(3-aminophenoxy)biphenyl in the presence of the diamine compoundand, when used, the tetracarboxylic acid dianhydride of the formula (IV)and successively continuing the reaction after adding phthalicanhydride.

(B) Carrying out the reaction of 4,4'-bis(3-aminophenoxy)biphenyl andthe diamine compound with phthalic anhydride and successively continuingthe reaction after adding pyromellitic dianhydride and, when used, thetetracarboxylic acid dianhydride of the formula (IV).

(C) Carrying out the reaction after simultaneously mixing pyromelliticdianhydride, 4,4'-bis(3-aminophenoxy)biphenyl, phthalic anhydride, thediamine compound and, when used, the tetracarboxylic acid dianhydride ofthe formula (IV).

The polyimide can also be prepared by suspending or dissolving4,4'-bis(3-aminophenoxy)biphenyl, pyromellitic dianhydride, phthalicanhydride and the diamine compound and, when used, the tetracarboxylicacid dianhydride of the formula (IV) in an organic solvent andsuccessively heating to carry out formation of a polyamic acid precursorand simultaneous imidization.

Films or powders of polyimides can be prepared by known methods.

The 4,4'-diaminodiphenyl ether is preferably employed an amount of fromabout 2 to about 30% by mole per mole of4,4-bis(3-aminophenoxy)biphenyl. When employed in an amount less thanabout 2% by mole, the processability is about the same as that of apolyimide consisting of recurring structural units of the formula (VI),and hence no improvement is observed. On the other hand, when employedin an amount greater than about 30% by mole, thermoplasticity isdrastically impaired, which is an essential characteristic of thepolyimide consisting of the recurring structural units of the formula(VI).

More preferably, the 4,4'-diaminodiphenyl ether is employed in an amountof from about 5 to about 20% by mole of4,4'-bis(3-aminophenoxy)biphenyl.

In this embodiment of the first aspect, the invention is carried out inthe presence of phthalic anhydride. A part of the phthalic anhydride maybe replaced by other dicarboxylic acid anhydrides so long as no adverseeffect on the good properties of polyimide is observed.

Exemplary suitable dicarboxylic anhydrides for use in partialreplacement include 2,3-benzophenonedicarboxylic anhydride,3,4-benzophenonedicarboxylic anhydride, 2,3-dicarboxyphenylphenyletheranhydride, 3,4-dicarboxyphenylphenylether anhydride,2,3-biphenyldicarboxylic anhydride, 3,4-biphenyldicarboxylic anhydride,2,3-dicarboxyphenylphenylsulfone anhydride,3,4-dicarboxyphenylphenylsulfone anhydride,2,3-dicarboxyphenylphenylsulfide anhydride,3,4-dicarboxyphenylphenylsulfide anhydride, 1,2-naphthalenedicarboxylicanhydride, 2,3-naphthalenedicarboxylic anhydride,1,8-naphthalenedicarboxylic anhydride, 1,2-anthracenedicarboxylicanhydride, 2,3-anthracenedicarboxylic anhydride and1,9-anthracenedicarboxylic anhydride.

Preferably, phthalic anhydride is employed in an amount of from about0.001 to about 1.0 mole per mole of the total diamine ingredients, i.e.,the sum of 4,4'-bis(3-aminophenoxy)biphenyl of the formula (I) and4,4'-diaminodiphenyl ether. When used in an amount less than about 0.001mole, thermal stability at high temperatures can not be achieved, whichis the object of this aspect of the invention. When used in an amountexceeding about 1.0 mole, a decrease in mechanical properties of thepolyimide results. Most preferably, the phthalic anhydride is employedin an amount of from about 0.01 to about 0.5 mole per mole of the totaldiamine ingredients.

It is particularly preferred to carry out the above reaction in anorganic solvent. Exemplary suitable organic solvents are set forthabove. The organic solvent may be used singly or as a mixture.

The reaction may be carried out in the organic solvent by any of thefollowing methods.

(A) Reacting pyromellitic dianhydride with4,4'-bis(3-aminophenoxy)biphenyl and 4,4'-diaminodiphenyl ether, andsuccessively continuing the reaction after adding phthalic anhydride.

(B) Reacting 4,4'-bis(3-aminophenoxy)biphenyl and 4,4'-diaminodiphenylether with phthalic anhydride, and successively continuing the reactionafter adding pyromellitic dianhydride.

(C) Simultaneously reacting pyromellitic dianhydride,4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-diaminodiphenyl ether andphthalic anhydride.

The reaction temperature is preferably about 250° C. or less, morepreferably about 50° C. or less. No particular limitation is placed onthe reaction pressure and the reaction can be sufficiently carried outat atmospheric pressure. The reaction time differs depending upon thesolvent and reaction temperature. A reaction time of from about 4 toabout 24 hours is usually satisfactory.

The polyamic acid thus obtained is imidized by heating at from about100° to about 400° C. or chemically imidized with an imidizing agentsuch as acetic anhydride to obtain a polyimide having recurringstructural units corresponding to the polyamic acid.

The polyimide can also be obtained by suspending or dissolving4,4'-bis(3-aminophenoxy)biphenyl, pyromellitic dianhydride,4,4'-diaminodiphenyl ether and phthalic anhydride in an organic solventand successively heating the resultant mixture to carry out formation ofa polyamic acid precursor and simultaneous imidization.

The polyimide of the first aspect of this invention obtained by theabove process contains two and more recurring structural unitsrepresented by the formula (V): ##STR17## wherein Q₁ and Q₂ are groupsselected from the group consisting of an aliphatic group, an alicyclicgroup, a monocyclic aromatic group, a fused polycyclic aromatic groupand a polycyclic aromatic group combined with a direct bond or via abridge member, Q₁ is a divalent group and Q₂ is a tetravalent group. Therecurring structural units of the formula (V) contains about 50% by moleor more of the recurring structural units of the formula (VI): ##STR18##and from about 0.5 to about 50% by mole of at least one recurringstructural unit of the formula (VII): ##STR19## wherein Q₂ is definedabove and R₁ is a divalent group derived from at least one of saiddiamine compounds.

When the recurring structural units of the formula (VI) are present inan amount of about 50 to about 85% by mole and the amount of therecurring structural units of the formula (VII) is from about 15 toabout 50% by mole, a non-crystalline polyimide is obtained.

When the recurring structural units of the formula (VI) are present inan amount of about 85% by mole or more, and the amount of the recurringstructural units of the formula (VII) is from about 0.5 to about 15% bymole, a crystalline or non-crystalline polyimide can be obtained bycontrolling the rate of crystallization.

The constitution of the above recurring structural units in thepolyimide obtained by the process of this invention cannot be identifiedas mentioned above. In practice, characteristic polyimide containing theabove recurring structural units can be obtained.

Physical properties were measured on several kinds of non-crystallinepolyimides obtained by the process of the first aspect of thisinvention. Ranges of the properties measured were Tg of 255° to 272° C.,5% weight loss temperature of 539° to 556° C. and heat distortiontemperature of the molded specimen of 240° to 255° C. On the other hand,crystalline polyimides consisting of the recurring structural units ofthe formula (VI) exhibited corresponding properties of respectively 260°C., 545° C. and 245° C. These results illustrate that these polyimidesare almost equal in heat resistance. The non-crystalline polyimidesobtained in this aspect of the invention had a melt viscosity of 10800to 40000 poises at 380° C. However, polyimides consisting of therecurring structural units of the formula (VI) did not flow at 380° C.The polyimide of this aspect of the invention has a melt flow initiationtemperature of 322° to 328° C., whereas the crystalline polyimide of theformula (VI) has a considerably high initiation temperature of 374° C.The non-crystalline polyimides of the first aspect of the inventionmaintain high thermal resistance and have improved processability.

In the melt processing of polyimides obtained by the first aspect of theinvention, a suitable amount of other thermoplastic resins may beblended depending upon the object for use, so long as there is noadverse effect on the objects of this aspect of the invention. Exemplarysuitable thermoplastic resins include polyethylene, polypropylene,polycarbonate, polyallylate, polyamide, polysulfone, polyether sulfone,polyether ketone, polyphenylene sulfide, polyamideimide, polyetherimideand modified polyphenylene oxide.

Fillers which are used for common resin compositions may be added in anamount which do not cause any adverse effect on the objects of the firstaspect of the invention. Exemplary suitable fillers include wearresistance improvers such as graphite, carborundum, silica powder,molybdenum disulfide and fluoro resins; reinforcing materials such asglass fibers, carbon fibers, boron fibers, silicon carbide fibers,carbon whiskers, asbestos, metallic fibers and ceramic fibers; flameretardance improvers such as antimony trioxide, magnesium carbonate andcalcium carbonate; electrical property improvers such as clay and mica;tracking resistance improvers such as asbestos, silica and graphite;acid resistance improvers such as barium sulfate, silica and calciummetasilicate; thermal conductivity improvers such as iron powder, zincpowder, aluminum powder and copper powder; and other miscellaneousmaterials such as glass beads, glass balloons, talc, diatomaceous earth,alumina, silicate balloons, hydrated alumina, metal oxides andcolorants.

The first aspect of the present invention provides non-crystallinepolyimides having improved processability without decreasing the thermalresistance of essentially crystalline polyimides, having meltviscosities lower than that of conventionally known polyimide resins,and which have excellent melt flow-stability.

The polyimides of this aspect of the invention are useful in precisionmolded products and thermal resistant films and as a non-crystallineengineering plastic having outstanding thermal resistance.

The first aspect of the present invention also provides a method forpreparing molded articles from noncrystalline to crystalline polyimidebase resins by arbitrarily adjusting the rate of crystallization. Hence,this aspect of the invention can provide excellent polyimide resinhaving remarkably improved processability and thermal resistance, and isan industrially valuable invention.

In the second aspect of the present invention, the aromaticpolyetherimide which is used is described in Polymer Preprint 24, (2),312-313 (1983). The polyetherimide is a polymer consisting of ether andimide linkages as a required bonding unit and is substantially composedof recurring units which are represented by the following formula:##STR20## wherein D is a trifunctional aromatic group where twofunctional groups out of three are connected with adjacent carbon atoms,both E and Ar₁ are residue of divalent aromatic groups. Representativeexamples of aromatic polyetherimide include the compounds represented bythe following formulas: ##STR21## Some of the above aromaticpolyetherimide are commercially available from General Electric Co. withTrade Marks such as ULTEM-1000, ULTEM-4000 and ULTEM-6000.

The polyimide which is used in the second aspect of the invention is acompound consisting of recurring units represented by the formula:##STR22## wherein X is a direct bond or --S--, and Y is a tetravalentgroup selected from the group consisting of an aliphatic group having atleast 2 carbon atoms, an alicyclic group, monocyclic aromatic group, afused polycyclic aromatic group and a polycyclic aromatic group wherearomatic groups are connected to each other with a direct bond or via abridge member.

As a diamine component of the polyimide, etherdiamine used isrepresented by the formula: ##STR23## wherein X is direct bond or --S--.

The etherdiamine is reacted with at least one tetracarboxylic aciddianhydride, and the resulting polyamic acid is subjected to dehydratingcondensation to obtain polyimide.

Examples of the etherdiamine used in the second aspect of the inventioninclude 4,4'-bis(3-aminophenoxy)biphenyl andbis[4-(3-aminophenoxy)phenyl]sulfide. The diamines may be used alone oras a mixture.

In addition, other diamines can be used in combination with theetherdiamine in a range which causes no adverse effect on theflowability of the molten polyimide. Diamines which may be used inadmixture with etherdiamine include, for example, m-aminobenzylamine,p-aminobenzylamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenylether, 4,4'-diaminodiphenylether, 3,3'-diaminodiphenyl sulfide,3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide,3,3'-diaminodiphenyl sulfone, 3,4'-diamino-diphenyl sulfone,4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone,3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone,1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene,1,4-bis(3-amino-phenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene,2,2-bis[4-(4-aminophenoxy)phenyl propane,4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)ketone,bis[4-(4-aminophenoxy)phenyl]sulfide,bis[4-(4-aminophenoxy)phenyl]sulfone,bis[4-(3-aminophenoxy)phenyl]methane,1,1-bis[4-(3-aminophenoxy)phenyl]-ethane,1,2-bis[4-(3-aminophenoxy)phenyl]ethane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane,2-[4-(3-aminophenoxy)phenyl]-2-[4-(3-aminophenoxy)-3-methylphenyl]propane,2,2-bis[4-(3-aminophenoxy)-3-methylphenyl]propane,2-[4-(3-aminophenoxy)phenyl]-2-[4-(3-aminophenoxy)-3,5-dimethylphenyl]propane,2,2-bis[4-(3-aminophenoxy)-3,5-dimethylphenyl]propane,2,2-bis[4-(3-aminophenoxy)phenyl]butane,2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1, 3,3,3-hexafluoropropane,4,4'-bis(3-aminophenoxy)biphenyl,4,4'-bis(3-aminophenoxy)-3-methylbiphenyl,4,4'-bis(3-aminophenoxy)-3,3'-dimethylbiphenyl,4,4'-bis(3-aminophenoxy)-3,5-dimethylbiphenyl,4,4'-bis(3-aminophenoxy)-3,3',5,5'-tetramethylbiphenyl,bis[4-(3-aminophenoxy)phenyl]ketone,bis[4-(3-aminophenoxy)phenyl]sulfide andbis[4-(3-aminophenoxy)phenyl]sulfone. These diamines are used inadmixture with etherdiamine of the above formula in an amount ofnormally not more than 30 wt. %, and preferably not more than 5 wt. %.

The polyimide used in the second aspect of the present invention can beprepared by reacting the diamine with tetracarboxylic acid dianhydridein an organic solvent and followed by conducting dehydratingcondensation.

The tetracarboxylic acid dianhydride used in this aspect of theinvention has the following formula: ##STR24## where Y is the same asabove. Representative examples of these tetracarboxylic aciddianhydrides include ethylenetetracarboxylic acid dianhydride,1,2,3,4-butanetetracarboxylic acid dianhydride,cyclopentanetetracarboxylic acid dianhydride, pyromellitic dianhydride,3,3'4,4'-benzophenonetetracarboxylic acid dianhydride,2,2'3,3'-benzophenonetetracarboxylic acid dianhydride,3,3'4,4'-biphenyltetracarboxylic acid dianhydride,2,2'3,3'-biphenyltetracarboxylic acid dianhydride, bis(3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl)sulfone dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl) methane dianhydride,bis(3,4-dicarboxyphenyl)methane dianhydride,2,3,6,7-naphthalenetetracarboxylic acid dianhydride,1,4,5,8-naphthalenetetracarboxylic acid dianhydride,1,2,5,6-naphthalenetetracarboxylic acid dianhydride,1,2,3,4-benzenetetracarboxylic acid dianhydride,3,4,9,10-perylenetetracarboxylic acid dianhydride,2,3,6,7-anthracenetetracarboxylic acid dianhydride,1,2,7,8-phenanthrenetetracarboxylic acid dianhydride,4,4'-(p-phenylenedioxy)diphthalic acid dianhydride and4,4'-(m-phenylenedioxy)diphthalic acid dianhydride. Among these aciddianhydrides, pyromellitic dianhydride,3,3'4,4'-benzophenonetetracarboxylic acid dianhydride,3,3'4,4'-biphenyltetracarboxylic acid dianhydride and 2,2-bis(3,4-dicarboxyphenyl) 1,1,3,3,3-hexafluoropropane dianhydride areparticularly preferred.

The tetracarboxylic acid dianhydrides can be used alone or as a mixtureof two or more.

The heat resistant resin composition of the second aspect of theinvention consists essentially of 95-5 wt. % of aromatic polyetherimideand 5-95 wt. % of polyimide. A preferred composition consists of 90-10wt. % of aromatic polyetherimide and 10-90 wt. % of polyimide. A morepreferred composition consists of 80-20 wt. % of aromatic polyetherimideand 20-80 wt. % of polyimide. When the content of aromaticpolyetherimide or polyimide is above 95 wt % or below 5 wt %, thecomposition of this aspect of the invention cannot provide a combinationof excellent characteristics such as flowability, mechanical strengthand particularly impact and abrasion resistances. That is, the secondaspect of the present invention provides the essential flowability ofaromatic polyetherimide with good mechanical strength and abrasionresistance of polyimide.

The composition of the second aspect of the invention may containfillers used in known resin compositions in an amount which has noadverse effect on the object of this aspect of the invention. Thefillers include abrasion resistance improvers such graphite,carborundum, silica powder, molybdenum disulfide and fluororesin;reinforcing materials such as glass fibers, carbon fibers, boron fibers,silicon carbide fibers, carbon whiskers, asbestos and metal fibers;flame retardance improvers such as antimony trioxide, magnesiumcarbonate and calcium carbonate; electrical property improvers such asclay and mica; tracking resistance improvers such as asbestos, silicaand graphite; acid resistance improvers such as barium sulfate, silicaand calcium metasilicate; thermal conductivity improvers such as ironpowder, zinc powder, aluminum powder and copper powder; and othermiscellaneous additives such as glass beads, glass spheres, talc,diatomaceous earth, alumina, silicate balloons, hydrated alumina, metaloxides, coloring agents and materials which are stable above 300° C.

These raw materials are used by mixing in advance. The mixing may becarried out by feeding each raw material separately to fusion mixingequipment or by mixing these materials in a general purpose mixer suchas Henschel mixer, ball mixer and ribbon blender prior to feeding thematerials to the fusion mixer.

Any procedure used for known resin compositions may be selected. Thetemperature of the fusion mixer is normally 250°-400° C. and preferably300°-380° C. Any molding process including compression molding, Sintermolding, injection molding and extrusion molding may be employed.Injection molding and extrusion molding are recommended from theviewpoints of the formation of a uniformly fused blend and highproductivity.

In the third aspect of the invention, the polyimide is derived frometherdiamine of the following formula: ##STR25## wherein Z is a directbond, thio radical or a phenylene dicarbonyl radical where two carbonylradicals are meta or para located on the benzene ring.

The etherdiamine is 4,4'-bis(3-aminophenoxy)biphenyl,bis[4-(3-aminophenoxy)phenyl]sulfide,1,3-bis[4-(3-aminophenoxy)benzoyl]benzene or1,4-bis[4-(3-aminophenoxy)benzoyl]benzene.

These etherdiamines have the following formulae respectively: ##STR26##The etherdiamine is reacted with at least one tetracarboxylic aciddianhydride in an organic solvent.

The tetracarboxylic acid dianhydride used in the above reaction is ananhydride of the formula: ##STR27## where Y is a tetravalent groupselected from the group consisting of an aliphatic group having at leasttwo carbon atoms, alicyclic group, a monocyclic aromatic group, a fusedpolycyclic aromatic group and a polycyclic aromatic group where aromaticgroups are connected to each other with a direct bond or via a bridgemember.

The tetracarboxylic acid dianhydride used in the method includes, forexample, ethylenetetracarboxylic dianhydride, butanetetracarboxylicdianhydride, cyclopentanetetracarboxylic dianhydride, pyromelliticdianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride,2,2',3,3'-benzophenonetetracarboxylic dianhydride,3,3'4,4'-biphenyltetracarboxylic dianhydride,2,2'3,3'-biphenyltetracarboxylic dianhydride,2,2-bis(3,4-dicarboxyphenyl)propane dianhydride,2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, bis(3,4-dicarboxyphenylether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride,1,1-bis-(2,3-dicarboxyphenyl)ethane dianhydride,bis(2,3-dicarboxyphenyl)methane dianhydride,bis(3,4-dicarboxyphenyl)methane dianhydride,4,4'-(p-phenylenedioxy)diphthalic dianhydride,4,4'-(m-phenylenedioxy)diphthalic dianhydride,2,3,6,7-naphthalenetetracarboxylic dianhydride,1,4,5,8-naphthalenetetracarboxylic dianhydride,1,4,5,8-naphthalenetetracarboxylic dianhydride,1,2,5,6-naphthalenetetracarboxylic dianhydride,1,2,3,4-benzenetetracarboxylic dianhydride,3,4,9,10-perylenetetracarboxylic dianhydride,2,3,6,7-anthracenetetracarboxylic dianhydride and1,2,7,8-phenanthrenetetracarboxylic dianhydride and 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride.

Particularly preferred tetracarboxylic acid dianhydrides arepyromellitic dianhydride, 3,3'4,4'-biphenyltetracarboxylic dianhydride,3,3',4,4'-benzophenonetetracarboxylic dianhydride andbis(3,4-dicarboxyphenyl)ether.

The tetracarboxylic acid dianhydride can be used alone or in themixtures of two or more.

The polyimide which is used in the composition of the third aspect ofthe invention is prepared by using the above stated etherdiamine as araw material. In order to obtain the composition of this aspect of theinvention, other diamines can also be used in combination with theetherdiamine within the range which has no adverse effect on the goodproperties of the polyimide.

Examples of the diamines which may be used in admixture with theetherdiamine include, m-phenylenediamine, o-phenylenediamine,p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, bis(3-aminophenyl) ether, (3-aminophenyl) (4-aminophenyl) ether, bis(4-aminophenyl) ether, bis (3-aminophenyl)sulfide, (3-aminophenyl)(4-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, bis(3-aminophenyl) sulfoxide, (3-aminophenyl) (4-aminophenyl) sulfoxide,bis (4-aminophenyl) sulfoxide, bis (3-aminophenyl)sulfone,(3-aminophenyl)(4-aminophenyl)sulfone, bis(4-aminophenyl)sulfone,3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone,4,4'-diaminobenzophenone, bis[4-(4-aminophenoxy)phenyl]methane,1,1-bis[4-(4-aminophenoxy)phenylethane,1,2-bis[4-(4-aminophenoxy)phenyl]ethane,2,2-bis[4-(4-aminophenoxy)phenyl]propane,2,2-bis[4-(4-aminophenoxy)phenyl]butane,2,2-bis(4-(4-aminophenoxy)phenyl-1,1,1,3,3,3-hexafluoropropane,1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene,1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene,4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ketone,bis[4-(4-aminophenoxy)phenyl]sulfide,bis[4-(4-aminophenoxy)phenyl]sulfoxide,bis[4-(4-aminophenoxy)phenyl]sulfone andbis[4-(4-aminophenoxy)phenyl]ether.

The high temperature engineering polymer which is used in the thirdaspect of the present invention includes, for example, polyphenylenesulfide, aromatic polysulfone and aromatic polyetherimide. However,aromatic polyetherimide is excluded when Z is a direct bond or thioradical in the formula of the polyimide used in this aspect of theinvention.

Polyphenylene sulfide is a resin having recurring units of the formula:##STR28## The preparation process of the resin is disclosed, for examplein U.S. Pat. No. 3,354,129 and Japanese Patent Publication TOKKOSHO45-3368 (1970). The resin can be commercially available, for example, asRYTON (Trade Mark of Phillips Petroleum Co. in U.S.A.). According to thepatent disclosure, polyphenylene sulfide is produced by reactingp-chlorobenzene with sodium sulfide monohydrate at 160°-250° C. underpressure in N-methylpyrrolidone solvent. Polyphenylene sulfide includesvarious grades such as from non-crosslinked to partially crosslinkedpolymers and polymers having different polymerization degrees. Thesegrades can be easily produced by conducting a post-treatment process andare also available in the market. Therefore grades having suitable meltviscosity for the desired polymer blend can be optionally prepared orpurchased in the market.

Aromatic polysulfone is a well known high temperature engineeringpolymer having a polymer chain represented by the formula: ##STR29## anddescribed, for example, by V. J. Leslie et al, in CHEMITECH, July 1975,426-432.

Representative examples of the recurring units constituting aromaticpolysulfone of this aspect of the invention include: ##STR30## Typicalaromatic polysulfones include, for example, polysulfone consisting ofrecurring units represented by the formula: ##STR31## (Trade Mark;VICTREX PES, commercially available from Imperial Chemical Industries inBritain) and polysulfone consisting of recurring units represented bythe formula: ##STR32## (Trade mark; UDEL POLYSULFONE, commerciallyavailable from Union Carbide Corp, in U.S.A.).

Grades of aromatic polysulfone having various polymerization degrees canbe easily produced. Therefore grades having suitable melt viscosity forthe desired polymer blend can be optionally selected.

Aromatic polyetherimide is a polymer having both ether and imidelinkages as a required bonding unit and is substantially composed ofrecurring units of the following formula: ##STR33## wherein F is atrivalent aromatic radical where two valences out of three are connectedwith two adjacent carbon atoms, and Ar₂ and G are respectively adivalent monoaromatic group and a divalent polycyclic aromatic groupconnected with a bridge member.

This polyetherimide is also a well known high temperature engineeringpolymer and is described, for example, by Takekoshi et al in PolymerPreprint 24,(2), 312-313 (1983).

Suitable examples of recurring units constituting aromaticpolyetherimide of this invention include: ##STR34## Aromaticpolyetherimide is commercially available from General Electric Co. inU.S.A. with the Trade Marks of ULTEM-1000, ULTEM-4000 and ULTEM-6000.

Aromatic polyetherimide particularly consisting of recurring units ofthe formula: ##STR35## is commercially available from General ElectricCo. with the Trade Mark of ULTEM-1000.

Grades of aromatic polyetherimide having various polymerization degreescan be easily produced. Therefore grades having suitable melt viscosityfor the desired polymer blend can be optionally selected.

The molding composition of resin in the third aspect of the invention isprepared so as to comprise the above mentioned polyimide in the range of99.9 to 50% by weight and the high-temperature engineering polymer inthe range of 0.1 to 50% by weight.

The resin of the third aspect of the invention based onpolyimide/polyphenylene sulfide exhibits remarkably low melt viscosityin a high temperature region above 350° C. The good fluidization effectof polyphenylene sulfide can be found even in a small amount. The lowerlimit of the amount in the composition is 0.1% by weight. The preferredamount is not less than 0.5% by weight.

Polyphenylene sulfide is excellent in chemical resistance, waterabsorption and flame retardance among the high-temperature stableresins. It, however, is inferior particularly in elongation at break andimpact resistance. Therefore, too much polyphenylene sulfide in theabove composition is unfavorable because the essential mechanicalstrength of polyimide can not be maintained. The amount of polyphenylenesulfide in the composition has an upper limit and is preferably 50% byweight or less.

The resin composition of this aspect of the invention based onpolyimide/aromatic polysulfone exhibits remarkably low melt viscosity ina high temperature region such as above 350° C. The good fluidizationeffect of aromatic polysulfone can be found even in a small amount. Thelower limit of amount in the composition is 0.1% by weight. Thepreferred amount is not less than 0.5% by weight.

Aromatic polysulfone is excellent in mechanical strength at hightemperatures among the high-temperature stable resins. It, however, isinferior to polyimide in mechanical strength, izod impact strength inparticular. Therefore, too much aromatic polysulfone in the abovecomposition is unfavorable because the essential mechanical strength ofpolyimide cannot be maintained. The amount of aromatic polysulfone inthe composition has an upper limit and is preferably 50% by weight orless.

The resin composition of this aspect of the invention based onpolyimide/aromatic polyetherimide exhibits remarkably low melt viscosityas compared with polyimide alone in a high temperature region, above360° C. in particular. The effect can be found even in a small amount ofaromatic polyetherimide. The lower limit in the composition is 0.1% byweight. The preferred amount is not less than 0.5% by weight.

Aromatic polyetherimide is excellent in mechanical strength at hightemperatures among the high-temperature stable resins. It, however, isinferior to polyimide in mechanical strength, izod impact strength inparticular. Therefore, too much aromatic polyetherimide is unfavorablebecause the essential mechanical strength of polyimide cannot bemaintained.

Aromatic polyetherimide is easily soluble in halogenated hydrocarbonssuch as methylene chloride and chloroform as well as amide type solventssuch as dimethyl acetamide and N-methyl-pyrrolidone. Therefore, too mucharomatic polyetherimide in the composition is unfavorable because theessential solvent resistance of polyimide cannot be maintained.

For these reasons, the amount of aromatic polyetherimide has an upperlimit in the composition and is preferably 50% by weight or less.

In the preparation of the composition in the third aspect of theinvention, common known methods can be employed and, for example, thebelow described methods are preferred.

(1) Polyimide powder and high-temperature engineering polymer powder arepre-mixed to prepare a uniform mixture of powder by using a blender suchas a mortar, Henschel mixer, drum blender, tumbler blender, ball mill orribbon blender.

(2) Polyimide powder is previously dissolved or suspended in an organicsolvent. High-temperature engineering polymer is added to the resultingsolution or suspension and dispersed uniformly, followed by removing thesolvent to give a powdered mixture.

(3) High-temperature engineering polymer is suspended in an organicsolvent solution of polyamic acid which is the precursor of polyimide inthis invention. The resultant suspension is imidized by heat treatmentat 100°-400° C. or by chemical imidization with a conventional imidizingagent, followed by removing the solvent to give a powdered mixture.

The powdered resin composition of polyimide thus obtained can be used asis for various molding applications such as injection molding,compression molding, transfer molding and extrusion molding. A morepreferred method is blending of fused resin prior to molding.

Fusion blending of polyimide and high-temperature engineering polymer inthe forms of, respectively, powder and powder, pellet and pellet, orpowder and pellet is also a simple and effective method.

Fusion blending can be carried out by using fusion blending equipmentfor usual rubber and plastics, for example, hot rolls, Banbury mixer,Brabender and extruder. The fusion temperature is set above the fusiontemperature of the formulated system and below the initiationtemperature of its decomposition. The temperature for blending polyimidewith polyphenylene sulfide is normally in the range of 300°-420° C. andpreferably in the range of 320°-400° C. The blending of polyimide witharomatic polysulfone or aromatic polyetherimide is carried out normallyin the range of 280°-420° C. and preferably in the range of 300°-400° C.

As to the method of molding the resin composition in this aspect of theinvention, injection and extrusion molding are suitable because thesemethods form a uniform blend of fused polymers and have a highproductivity. Other processing methods such as transfer molding,compression molding and sinter molding may also be applied.

In addition, the resin composition of the third aspect of the inventionmay contain at least one solid lubricant such as molybdenum disulfide,graphite, boron nitride, lead monoxide and lead powder. The compositionmay also contain at least one reinforcing material such as glass fibers,carbon fibers, aromatic polyamide fibers, potassium titanate fibers andglass beads.

The resin composition of this aspect of the invention may also containat least one commonly used additive within the range which has noadverse effect on the object of this invention. Such additives include,for example, antioxidants, heat stabilizers, ultraviolet ray absorbers,flame retardants, auxiliary flame retardants, antistatic agents,lubricants and coloring agents.

In the fourth aspect of the invention, the polyimides may be prepared bythe process disclosed in the above-mentioned Japanese Laid-open PatentNo. 143478/1986, which comprises reacting an ether diamine representedby the formula: ##STR36## where Z is a direct bond or is ##STR37##Examples of diamines for use in the invention are4,4'-bis(3-aminophenoxy)biphenyl; bis[4-(3-aminophenoxy)phenyl]sulfide;1,4-bis[4-(3-aminophenoxy)benzoyl]benzene; and1,3-bis[4-(3-aminophenoxy)benzoyl]benzene.

Any diamine other than the above-mentioned ether diamines, can be usedin mixture therewith within such a range that good physical propertiesof the polyimide is not impaired. Examples of such a diamine are asfollows: m-phenylenediamine, o-phenylenediamine, p-phenylenediamine,m-aminobenzylamine, p-aminobenzylamine, bis(3-aminophenyl)ether,(3-aminophenyl)(4-aminophenyl)ether, bis(4-aminophenyl)ether,bis(3-aminophenyl)sulfide, (3-aminophenyl) (4-aminophenyl) sulfide, bis(4-aminophenyl) sulfide, bis(4-aminophenyl) sulfide, bis (3-aminophenyl)sulfoxide, (3-aminophenyl) (4-aminophenyl) sulfoxide, bis(4-aminophenyl)sulfoxide, bis(3-aminophenyl)sulfone,(3-aminophenyl)(4-aminophenyl)sulfone, bis(4-aminophenyl)sulfone,3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone,4,4'-diaminobenzophenone, bis[4-(3-aminophenoxy)phenyl]methane,bis[4-(4-aminophenoxy)phenyl]methane,1,1-bis[4-(3-aminophenoxy)phenyl]ethane,1,1-bis[4-(4-aminophenoxy)phenyl]ethane,1,2-bis[4-(3-aminophenoxy)phenyl]ethane,1,2-bis[4-(4-aminophenoxy)phenyl]ethane,2,2-bis[4-(3-aminophenoxy)phenyl]propane,2,2-bis[4-(4-aminophenoxy)phenyl]propane,2,2-bis[4-(3-aminophenoxy)phenyl]butane,2,2-bis[4-(4-aminophenoxy)phenyl]butane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane,2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,13,3,3-hexafluoropropane,1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene,1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene,4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(3-aminophenoxy)phenyl]ketone,bis[4-(4-aminophenoxy)phenyl]ketone,bis[4-(4-aminophenoxy)phenyl]sulfide,bis[4-(4-aminophenoxy)phenyl]sulfoxide,bis[4-(4-aminophenoxy)phenyl]sulfone,bis[4-(4-aminophenoxy)phenyl]sulfone,bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether,etc.

Tetracarboxylic dianhydrides for use in preparation of polyimides of thefourth aspect of the invention are represented by the formula: ##STR38##where Y is a tetravalent group selected from the group consisting of analiphatic group having at least 2 carbon atoms, an alicyclic group, amonocyclic aromatic group, a fused polycyclic aromatic group, and apolycyclic aromatic group where the aromatic groups are connecteddirectly or via a bridge member and typical examples of these areethylenetetracarboxylic acid dianhydride, butanetetracarboxylic aciddianhydride, cyclopentanetetracarboxylic acid dianhydride, pyromelliticdianhydride, 3,3,-4,4'-benzophenonetetracarboxylic acid dianhydride,2,2'3,3'-benzophenonetetracarboxylic acid dianhydride,3,3'4,4'-biphenyltetracarboxylic dianhydride,2,2'3,3'-biphenyltetracarboxylic acid dianhydride,2,2-bis(3,4-dicarboxyphenyl)propane dianhydride,2,2-bis(2,3-dicarboxyphenyl)propane dianhydride,bis(3,4-dicarboxyphenylether dianhydride,bis(3,4-dicarboxyphenyl)sulfone dianhydride,1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride,bis(2,3-dicarboxyphenyl)methane dianhydride,bis(3,4-dicarboxyphenyl)methane dianhydride,4,4'-(p-phenylenedioxy)diphthalic acid dianhydride,4,4'-(m-phenylenedioxy)diphthalic acid dianhydride,2,3,6,7-naphthalenetetracarboxylic acid dianhydride,1,4,5,8-naphthalenetetracarboxylic acid dianhydride,1,2,5,6-naphthalenetetracarboxylic acid dianhydride,1,2,3,4-benzenetetracarboxylic acid dianhydride,3,4,9,10-perylenetetracarboxylic acid dianhydride,2,3,6,7-anthracenetetracarboxylic acid dianhydride, and1,2,7,8-phenanthrenetetracarboxylic acid dianhydride and 2,2-bis(3,4-dicarboxyphenyl)1,1,1,3,3,3-hexafluoropropane dianhydride. Thesemay be used alone or in combination of at least two.

Particularly preferred radicals in the Y defined above are tetravalentradicals represented in the formulas: ##STR39## Aromatic polyamideimidessuitable for use in the fourth aspect of the invention are polymershaving as a repeating unit in the main chain a condensation product ofimide and amide interconnected, which is represented by formula:##STR40## where Ar₃ is a trivalent aromatic radical having at least onebenzene ring, and J is a divalent organic radical.

Particularly preferred aromatic polyamideimides are the condensationpolymers having a repeating unit represented by the following formulas:##STR41## An example of aromatic polyamideimide is commerciallyavailable under the trade name, TORLON® (Amoco Chemicals Corp., USA).

The resin composition to be molded according to the fourth aspect of theinvention is composed of the above-mentioned polyimide of 99.9 to 50% byweight, and the aromatic polyamideimide of 0.1 to 50% by weight, the sumamounting to 100% by weight.

The resin composition according to the fourth aspect of the inventionconsisting of the polyimide and the aromatic polyamideimide may beaffected with even a small content of the latter with improvement inheat resistance and/or mechanical strength. The lower limit of thelatter is 0.1% by weight, preferably 0.5% by weight.

Aromatic polyamideimides have very high melt viscosity compared withconventional thermoplastic resins, and therefore, too much aromaticpolyamideimide in the resin composition produces unfavorable results,i.e., their moldability falls to an insufficient level, together with adrop in elongation at break. Thus the maximum content of aromaticpolyamideimide is limited, and is preferably 50% by weight or less.

The resin composition according to the fourth aspect of the inventioncan usually be prepared by known methods, for example:

(1) A polyimide powder and an aromatic polyamideimide powder treated bymixing and/or kneading by means of a mortar, Henschel mixer, drumblender, tumbler blender, ball mill or ribbon blender to obtain thedesired powder.

(2) A polyimide powder is dissolved or suspended in an organic solvent.To the solution or suspension, an aromatic polyamideimide is added, andmade to be uniformly dispersed or dissolved. Then the solvent is removedto obtain the desired powder.

(3) An aromatic polyamideimide is dissolved or suspended in a solutionof a polyamide acid in an organic solvent, which is the precursor of thepolyimide according to this aspect of the invention, and then convertedinto an imide by heating to 100° to 400° C. or in the presence of ausual imidization agent. Then the solvent is removed to obtain thedesired powder.

The thus-obtained powdery polyimide composition is subjected, preferablyafter melt-blending, to various processes, for example, injection,compression, transfer or extrusion molding. Especially, in thepreparation of the resin composition, a simple and effective method isto melt-blend both components in the form of powders or pellets or onecomponent of powders and the other component of pellets.

The melt-blending can be accomplished by usual means for blendingrubbers or plastics, such as a hot roll, Banbury mixer, Brabender orextruder. The melting temperature may be set within the temperaturerange where the mixture can be caused to melt without thermaldecomposition, usually 280° to 420° C., preferably 300° to 400° C.

For molding the resin composition of the fourth aspect of the invention,injection and extrusion moldings permitting formation of a uniformmelt-blend with high productivity are preferred. Additionally, transfer,compression or sintering molding, or film extrusion may be applied.

The resin composition of the fourth aspect of the invention may containas additives at least one solid lubricant selected from molybdenumdisulfide, graphite, boron nitride, lead monoxide, lead powder, etc. andat least one reinforcing material selected from glass fibers, carbonfibers, aromatic polyamide fibers, silicon carbide fibers, potassiumtitanate fibers, glass beads, etc.

In addition, the resin composition may contain at least one additiveselected from antioxidants, thermal stabilizers, ultraviolet rayabsorbers, fire retardants, fire-retardant-activity enhancing agents,antistatic agents, lubricants, coloring agents, etc.

The invention will be further clarified by the following examples whichare intended to be purely exemplary of the various aspects of thepresent invention wherein Examples 1-23 and Comparative Examples 1-9relate to the first aspect of the invention, Examples 24-41 andComparative Examples 10-14 relate to the second aspect of the invention,Examples 42-106 and Comparative Examples 15-39 relate to the thirdaspect of the invention, and Examples 107-131 and Comparative Examples40-49 relate to the fourth aspect of the invention.

In the examples related to the first aspect of the invention, theproperties in the examples and comparative examples were measured by thefollowing methods.

Inherent Viscosity: After dissolving 0.50 g of polyimide powder in 100ml of a solvent mixture of p-chlorophenol/phenol (9/1 weight ratio) byheating, the viscosity was measured at 35° C.

Tg, Tm and Tc: DSC (Shimadzu DT-40 series, DSC 41M) was used for themeasurement.

Crystallinity: XRD (Rikadenki RAD-RVC Series, X-ray diffractometer) wasused for the measurement.

Heat distortion temperature: ASTM, D-648I was used for the measurement.

Melt Viscosity: Shimadzu KOKA-model Flow Tester, CFT 500A was used under100 kg load for the measurement.

Melt flow initiation temperature: Shimadzu KOKA-model Flow Tester, CFR500A was used, and the melt flow initiation temperature was measuredunder 100 kg load.

5% Weight-Loss Temperature: Shimadzu DTA-TG was used in air for themeasurement.

EXAMPLE 1

Into a reaction vessel equipped with a stirrer, reflux condenser, waterseparator and nitrogen inlet tube, 1.9872 kg (5.4 moles) of4,4'-bis(3-aminophenoxy)biphenyl, 0.12 kg (0.6 mole) of4,4'-diaminodiphenyl ether, 1.2426 kg (5.7 moles of pyromelliticdianhydride, 0.0888 kg (0.6 mole) of phthalic anhydride and 13.4 kg ofcresylic acid were charged. The mixture obtained was heated to 145° C.with stirring in a nitrogen atmosphere while distilling off about 200 ccof water. The reaction was continued for 4 hours at 145° C.

After the reaction mixture was cooled to room temperature, about 7 kg ofmethyl ethyl ketone were charged and filtered to obtain polyimide as ayellow powder. The polyimide powder was washed with methyl ethyl ketoneand dried at 180° C. for 24 hours under reduced pressure to obtain 3.16kg of the product. The yield was 98%. The polyimide powder had aninherent viscosity of 0.50 dl/g and a glass transition temperture of259° C. Tc and Tm were not observed. Melt viscosity was 14000 poise at380° C. and 7000 poise at 400° C.

Comparative Example 1

Into the same reaction vessel as described in Example 1, 2.208 kg (6moles) of 4,4'-bis(3-aminophenoxy)biphenyl, 1.2426 kg (5.7 moles) ofpyromellitic dianhydride, 0.0888 kg (0.6 mole) of phthalic anhydride and13.4 kg of cresylic acid were charged. The same procedures as describedin Example 1 were carried out and 3.27 kg of polyimide were obtained asyellow powder. The yield was 98.5%. The polyimide powder obtained had aninherent viscosity of 0.50 dl/g, a Tg of 260° C., a Tc of 332° C. and aTm of 384° C. The polyimide had a melt viscosity of 7500 poise at 400°C. and did not flow at all at 380° C.

EXAMPLE 2

Into the same reaction vessel as described in Example 1, 2.208 kg (6moles) of 4,4'-bis(3-aminophenoxy)biphenyl, 1.1183 kg (5.13 moles) ofpyromellitic dianhydride, 0.1676 kg (0.57 mole) of3,3',4,4'-biphenyltetracarboxylic dianhydride, 0.0888 kg (0.6 mole) ofphthalic anhydride and 13.4 kg of cresylic acid were charged. The sameprocedures as described in Example 1 were carried out and 3.3 kg ofyellow polyimide powder were obtained. The yield was 98%. The polyimidepowder had an inherent viscosity of 0.48 dl/g and a Tg of 255° C. Tc andTm were not observed. The melt viscosity was 16000 poise at 380° C.

EXAMPLE 3

Into the same reaction vessel as described in Example 1, 3.312 kg (9moles) of 4,4'-bis(3-aminophenoxy)biphenyl, 0.2 kg (1 mole) of4,4'-diaminodiphenyl ether and 17.58 kg of N,N-dimethylacetamide werecharged. To the solution obtained, 2.126 kg (9.75 moles) of pyromelliticdianhydride were added by portions in a nitrogen atmosphere at roomtemperature with caution to inhibit temperature rise of the solution.The resulting mixture was stirred for about 20 hours at roomtemperature. A part of the polyamide acid solution thus obtained wascast on a glass plate and heated for each for 1 hour at 100° C., 200° C.and 300° C. to obtain a transparent light yellow polyimide film having athickness of 25 μm. The polyimide film had a tensile strength of 16.5kg/mm², elongation of 80% in accordance with ASTM D-882, and 5% weightloss temperature of 550° C. by DTA-TG.

EXAMPLES 4 TO 8 AND COMPARATIVE EXAMPLES 2 AND 3

The same reaction vessel as described in Example 1 and the procedures ofExample 1 were repeated except that the diamines employed the amountsthereof were changed as illustrated in Table 1. The results aresummarized in Table 1.

Tg, 5% weight loss temperature, melt viscosity, melt flow initiationtemperature and heat distortion temperature of molded specimen aresummarized in Table 2 for Examples 1, 2, 4 to 8 and Comparative Examples1 and 2.

                                      TABLE 1                                     __________________________________________________________________________           Tetracarboxylic                                                                       Diamine ingredient           Inherent      Melt                Example or                                                                           acid    4,4'-bis(3-aminoph-          viscosity     viscosity           Comparative                                                                          dianhydride                                                                           enoxy)biphenyl                                                                          Auxiliary diamine                                                                           Yield                                                                              (η)                                                                            Tg Tc Tm (poise/             Example                                                                              kg(mole)                                                                              kg(mole)  kg(mole)      (%)  (dl/g)                                                                             (°C.)                                                                     (°C.)                                                                     (°C.)                                                                     380°         __________________________________________________________________________                                                              C.)                 Ex. 4  Pyromellitic                                                                          1.9872 (5.4)                                                                            3,4'-diaminodiphenyl ether                                                                  98   0.481                                                                              260                                                                              No No 10800                      dianhydride       0.12 (0.6)                                                  1.2496 (5.7)                                                           Ex. 5  ↑ ↑   3,3'-diaminodiphenyl ether                                                                  98   0.478                                                                              258                                                                              ↑                                                                          ↑                                                                          11600                                        0.12 (0.6)                                           Comp.  ↑ 0.8832 (2.4)                                                                            4,4'-diaminodiphenyl ether                                                                  gelation                                                                           Impossible to measure             Ex. 3                    0.72 (3.6)                                           Ex. 6  ↑ 1.9872 (5.4)                                                                            bis[4-{4-(4-aminophenoxy)                                                                   97.5 0.508                                                                              258                                                                              No No 10800                                        phenoxyl} phenyl]sulfone                                                      0.3696 (0.6)                                         Ex. 7  ↑  1.104 (3.0)                                                                            4,4'-bis[4-(4-amino-α, α-                                                       97   0.538                                                                              272                                                                              ↑                                                                          ↑                                                                          40000                                        dimethylbenzyl)phenoxy]                                                       diphenyl sulfone                                                              1.336 (3.0)                                          Ex. 8  ↑ 1.9872 (5.4)                                                                            4,4'-bis[4-(4-amino-α, α-                                                       97   0.510                                                                              259                                                                              ↑                                                                          ↑                                                                          12300                                        dimethylbenzyl)phenoxy]                                                       diphenyl sulfone                                                              0.4008 (0.6)                                         Comp.  Pyromellitic                                                                           2.1896 (5.95)                                                                          4,4'-diaminodiphenyl ether                                                                  98   0.481                                                                              260                                                                              332                                                                              384                                                                              No flow             Ex. 2  dianhydride       0.010 (0.05)                                                1.2426 (5.7)                                                           __________________________________________________________________________

                  TABLE 2                                                         ______________________________________                                        Example        5% weight Heat           Melt                                  or             loss      distortion                                                                            Melt   initiation                            Compar-        temper-   temper- viscosity                                                                            temper-                               ative  Tg      ature     ature   (poise/                                                                              ature                                 Example                                                                              (°C.)                                                                          (°C.)                                                                            (°C.)                                                                          380° C.)                                                                      (°C.)                          ______________________________________                                        Ex. 1  259     555       244     14000  327                                   Ex. 2  255     553       240     16000  322                                   Ex. 4  260     556       245     10800  326                                   Ex. 5  258     550       243     11600  325                                   Ex. 6  258     546       243     10800  324                                   Ex. 7  272     539       255     40000  335                                   Ex. 8  259     540       244     12300  324                                   Comp.  260     545       245     No flow                                                                              374                                   Ex. 1                                                                         Comp.  260     546       246     ↑                                                                              372                                   Ex. 2                                                                         ______________________________________                                    

EXAMPLE 9

Into the same reaction vessel as described in Example 1, 3,312 kg (9.0moles) of 4,4'-bis(3-aminophenoxy)biphenyl, 0.2 kg (1.0 mole) of4,4'-diaminodiphenyl ether, 2,071 kg (9.5 moles) of pyromelliticdianhydride, 0.148 kg (1.0 mole) of phthalic anhydride and 21.58 kg ofcresylic acid were charged. The mixture was heated to 145° C. withstirring in a nitrogen atmosphere while distilling out about 350 cc ofwater. The reaction was continued for 4 hours at 145° C. After thereaction mixture was cooled to room temperature, 10.8 kg of methyl ethylketone were charged and filtered. The yellow polyimide powder obtainedwas washed with methyl ethyl ketone and dried at 180° C. for 24 hours.The amount obtained was 5.26 kg (98% yield). The polyimide powder had aninherent viscosity of 0.50 dl/g and a glass transition temperature (Tg)of 260° C. The polyimide powder was extruded to 400° C. with a Takayasumodel extruder having a diameter of 25 mm to obtain red browntransparent pellets. The pellets were further extruded to obtain a redbrown transparent flexible film having a width of 50 mm and a thicknessof 100 μm.

The rate of crystallization was measured on the polyimide film thusobtained by changing the standing time in a Geer oven at 300° C. Theresults are illustrated in FIG. 1. No crystallization was found at alluntil a standing time of 100 minutes in the Geer oven and 25%crystallinity was observed after 400 minutes.

Comparative Example 4

Into the same reaction vessel as described in Example 1, 3.680 kg (10moles) of 4,4'-bis(3-aminophenoxy)biphenyl, 2.071 kg (9.5 moles) ofpyromellitic dianhydride, 0.148 kg (1.0 mole) of phthalic anhydride and21.53 kg of cresylic acid were charged. The same procedures as describedin Example 1 were carried out to obtain 5.46 kg of yellow polyimidepowder. The yield was 98.5%. The polyimide powder had an inherentviscosity of 0.50 dl/g. An extruded film was prepared from the polyimidepowder by the same procedures as described in Example 10 and the rate ofcrystallization was measured. Results are illustrated in FIG. 2.

Crystallization was initiated after standing for about 5 minutes in theGeer oven at 300° C. and 25% crystallinity was observed after 30minutes.

EXAMPLE 10

Into the same reaction vessel as described in Example 1, 3.680 kg (10moles) of 4,4'-bis(3-aminophenoxy)biphenyl, 1.864 kg (8.55 moles) ofpyromellitic dianhydride, 0.279 kg (0.95 mole) of3,3',4,4'-biphenyltetracarboxylic dianhydride, 0.148 kg (1.0 mole) ofphthalic anhydride and 21.5 kg of cresylic acid were charged. The sameprocedures as described in Example 1 were carried out to obtain 5.51 kgof yellow polyimide powder. The yield was 98.2%. The polyimide powderhad an inherent viscosity of 0.48 dl/g. An extruded film was preparedfrom the polyimide powder by the same procedures as described in Example9 and the rate of crystallization was measured.

The results are illustrated in FIG. 1. Crystallization was not observedat all until 180 minutes after standing in the Geer oven at 300° C. and25% crystallinity was observed after 500 minutes.

EXAMPLES 11 TO 13 AND COMPARATIVE EXAMPLE 5

The same reaction vessel as described in Example 1 was used and theprocedures of Example 1 were repeated except that the amount of4,4'-diaminodiphenyl ether was varied. The results are summarized inTable 3 and FIG. 2.

As understood from Table 3 and FIG. 2, addition of 4,4'-diaminodiphenylether in an amount of 25% by mole or less of4,4'-bis(3-aminophenoxy)biphenyl can control the rate ofcrystallization. The control range is from 5 to 90 minutes in theinitiation time of crystallization and from 300 to 3000 minutes in thetime required for providing 25% crystallinity. Thus polyimides having adifferent rate of crystallization can be arbitrarily prepared.

                                      TABLE 3                                     __________________________________________________________________________                                                       Crystallization rate              Diamine ingredient      Tetracarboxylic     of extruded film           Example or           (Diamine B/                                                                             acid        Inherent                                                                              Initiation                                                                         Time to 25%           Comparative                                                                          Diamine A*.sup.1                                                                     Diamine B*.sup.2                                                                     Diamine A) × 100                                                                  dianhydride                                                                           yield                                                                             viscosity                                                                          Tg time                                                                               crystallinity         Example                                                                              kg(mole)                                                                             kg(mole)                                                                             mole(%)   kg(mole)                                                                              (5) (dl/g)                                                                             (°C.)                                                                     /300° C.)                                                                   (min/300°                                                              C.)                   __________________________________________________________________________    Ex. 9  3.312  0.200  11.1      PMDA*.sup.3                                                                           98.0                                                                              0.50 258                                                                              100  400                          (9.5)  (1.0)            2.71 (9.5)                                     Ex. 11 3.496  0.100  5.3       ↑ 98.5                                                                              0.51 258                                                                              50   100                          (9.0)  (1.0)                                                           Ex. 12 3.202  0.260  14.9      ↑ 98.0                                                                              0.51 261                                                                              450  1000                         (8.7)  (1.3)                                                           Ex. 13 2.944  0.400  25.0      ↑ 98.5                                                                              0.52 260                                                                              900  3000                         (8.0)  (2.0)                                                           Comp. Ex. 4                                                                          3.680  0      0         ↑ 98.5                                                                              0.50 260                                                                               5    30                          (10.0)                                                                 Comp. Ex. 5                                                                          2.576  0.600  43.0      ↑ 98.5                                                                              0.53 260                                                                              Do not crysyallize                (7.0)  (3.0)                                after 5000                 __________________________________________________________________________                                                       min.                        Note: *.sup.1 4,4Bis(3-aminophenoxy)biphenyl                                  *.sup.2 4,4Diaminodiphenyl ether                                              *.sup.3 Pyromellitic dianhydride                                         

EXAMPLE 14

The same reaction vessel as described in Example 1 was charged with3.312 kg (9 moles) of 4,4'-bis(3-aminophenoxy)biphenyl, 0.2 kg (1.0mole) of 4,4'-diaminodiphenyl ether and 31.5 kg ofN-methyl-2-pyrrolidone. To the mixture obtained, 2.071 kg (9.5 moles) ofpyromellitic dianhydride were added by portions at room temperature in anitrogen atmosphere with caution to inhibit the temperature rise of thesolution. Stirring was continued for 20 hours at room temperature. Tothe resulting polyamic acid solution, 0.444 kg (3 moles) of phthalicanhydride were added at room temperature in a nitrogen atmosphere andstirred for an additional hour. Successively 0.14 kg of τ-picoline and0.408 kg (4 moles) of acetic anhydride were added dropwise to thesolution. Yellow polyimide powder started to precipitate after an hourof completing addition of the dropwise addition. After stirring furtherfor 10 hours at room temperature, the reaction mixture was filtered,washed by dispersing in methyl ethyl ketone, filtered again and dried at180° C. for 24 hours. Polyimide powder thus obtained was 5.26 kg. Theyield was 98%. The polyimide powder had a Tg of 258° C., an inherentviscosity of 0.50 dl/g and a melt viscosity of 7000 poise at 400° C.

EXAMPLE 15

Into the same reaction vessel as described in Example 1. 1.9872 kg (5.4moles) of 4,4'-bis(3-aminophenoxy)biphenyl, 0.12 kg (0.6 mole) of4,4'-diaminodiphenyl ether, 1.2426 kg (5.7 moles) of pyromelliticdianhydride, 0.0888 kg (0.6 mole) of phthalic anhydride and 13.4 kg ofcresylic acid were charged. The mixture were heated to 145° C. withstirring in a nitrogen atmosphere while about 200 cc of water weredistilled out. The reaction was further continued for 4 hours at 145° C.After cooling the reaction mixture to room temperature, about 7 kg ofmethyl ethyl ketone were added to the mixture and filtered. Theresulting yellow powder was washed with methyl ethyl ketone and dried at180° C. for 24 hours under reduced pressure to obtain 3.16 kg ofpolyimide powder. The yield was 98%. The polyimide had an inherentviscosity of 0.50 dl/g, a Tg of 259° C., and a melt viscosity of 14000poise at 380° C. and 7000 poise at 400° C. Tc and Tm was not observed.

Molding stability of polyimide thus obtained was measured by varyingresidence time in the cylinder of the flow tester at 420° C. underpressure of 100 kg/cm². Results are illustrated in FIG. 3. Longerresidence time in the cylinder has almost no effect on melt viscosity,which fact indicates good thermal stability.

Comparative Example 6

Into the same reaction vessel as described in Example 1, 2.208 kg (6moles) of 4,4'-bis(3-aminophenoxy)biphenyl, 1.2426 kg (5.7 moles) ofpyromellitic dianhydride, 0.0888 kg (0.6 mole) of phthalic anhydride and13.4 kg of cresylic acid were charged. The same procedures as describedin Example 1 were carried out to obtain 3.27 kg of yellow polyimidepowder. The yield was 98.5%. The polyimide powder had an inherentviscosity of 0.50 dl/g, a Tg of 260° C., a Tc of 332° C. and a meltviscosity of 7500 poise at 400° C. The polyimide powder exhibited nomelt flow at 380° C.

EXAMPLES 16 TO 19 AND COMPARATIVE EXAMPLES 7 AND 8

The same reaction vessel as described in Example 1 was used, and theprocedures of Example 14 were repeated except that the amount of4,4'-diaminodiphenyl ether was varied as illustrated in Table 4. Theresults are summarized in Table 4.

                                      TABLE 4                                     __________________________________________________________________________    Example                  Phthalic                  5% Weight                  or   Diamine ingredient  anhydride ingredient      loss  Melt                 Compar-                                                                            Diamine                                                                            Diamine                                                                            (Diamine B/    Phthalic anhydide                                                                          Inherent                                                                              temper-                                                                             viscosity            ative                                                                              A*.sup.1                                                                           B*.sup.2                                                                           Diamine A) × 100                                                                  Amount                                                                             /Diamine(A + B)                                                                        Yield                                                                             viscosity                                                                          Tg ature (poise/              Example                                                                            kg(mole)                                                                           kg(mole)                                                                           (mole %)  kg(mole)                                                                           (mole ratio)                                                                           (%) (dl/g)                                                                             (°C.)                                                                     (°C.)                                                                        380°          __________________________________________________________________________                                                             C.)                  Ex. 14                                                                             3.3120                                                                             0.200                                                                              11.1      0.444                                                                              0.3      98.0                                                                              0.50 258                                                                              548   14000                     (9.0)                                                                              (1.0)          (0.6)                                                Ex. 15                                                                             1.9872                                                                             0.120                                                                              11.1      0.0888                                                                             0.1      98.0                                                                              0.50 259                                                                              555   14000                     (5.4)                                                                              (0.6)          (0.6)                                                Ex. 16                                                                             2.0976                                                                             0.060                                                                              5.3       ↑                                                                            ↑  98.0                                                                              0.51 258                                                                              550   19000                     (5.7)                                                                              (0.3)                                                               Ex. 17                                                                             2.0424                                                                             0.900                                                                              8.1       ↑                                                                            ↑  97.5                                                                              0.50 260                                                                              552   15800                     (5.55)                                                                             (0.45)                                                              Ex. 18                                                                             1.9320                                                                             0.150                                                                              14.3      ↑                                                                            ↑  98.0                                                                              0.51 262                                                                              551   19300                     (5.25)                                                                             (0.75)                                                              Ex. 19                                                                             1.8768                                                                             0.180                                                                              17.6      ↑                                                                            ↑  98.5                                                                              0.52 262                                                                              549   22300                     (5.10)                                                                             (0.9)                                                               Comp.                                                                              1.5456                                                                             0.360                                                                              42.9      ↑                                                                            ↑  98.5                                                                              0.53 260                                                                              549   204000               Ex. 8                                                                              (4.2)                                                                              (1.8)                                                               Comp.                                                                              2.2080                                                                             0    0         ↑                                                                            ↑  98.5                                                                              0.50 260                                                                              545   No flow              Ex. 6                                                                              (6)                                                                      Comp.                                                                              2.1896                                                                             0.010                                                                              0.84      ↑                                                                            ↑  98.0                                                                              0.48 260                                                                              550   No flow              Ex. 7                                                                              (5.95)                                                                             (0.05)                                                              __________________________________________________________________________     *.sup.1 4,4bis(3-aminophenoxy)-biphenyl                                       *.sup.2 4,4diaminodiphenylether                                          

EXAMPLE 20

The same procedures as described in Example 15 were carried out withoutusing phthalic anhydride to obtain yellow polyimide powder. Thepolyimide powder had a Tg of 260° C. and an inherent viscosity of 0.50dl/g.

Melt viscosity of the polyimide powder was measured by varying theresidence time in the cylinder of the flow tester as carried out inExample 15. Results are illustrated in FIG. 3. Longer residence time ledto higher viscosity. Thus thermal stability of the polyimide wasinferior to that of Example 15.

EXAMPLE 21

The same reaction vessel as described in Example 1 was charged with1.9872 kg (5.4 moles) of 4,4'-bis(3-aminophenoxy)biphenyl, 0.120 kg (.06mole) of bis(4-aminophenoxy) ether, 1.1183 kg (5.13 moles) ofpyromellitic dianhydride, 0.1676 kg (057 mole) of3,3'4,4'-biphenyltetracarboxylic dianhydride and 13.4 kg of cresylicacid. The mixture was heated to 145° C. with stirring in a nitrogenatmosphere while about 200 cc of water were distilled out. The reactionwas further continued for 4 hours at 145° C. After cooling the reactionmixture to room temperature, about 7 kg of methyl ethyl ketone werecharged and filtered. The resulting yellow-powder was washed with methylethyl ketone and dried at 180° C. for 24 hours under reduced pressure.The polyimide powder obtained was 3.184 kg. The yield was 97.5%. Thepolyimide powder had an inherent viscosity of 0.49 dl/g, a Tg of 255° C.and a melt viscosity of 10000 poise at 380° C. Tc and Tm were notobserved.

Comparative Example 9

The same reaction vessel described in Example 1 was used to react thefollowing reactants:

    ______________________________________                                        primary amine      4.5 mole (75%)                                             4,4'diaminodiphenyl ether                                                                        1.5 mole (25%) (33.3                                                          mole %/primary amine)                                      Pyromellitic dianhydride                                                                         5.7 mole                                                   ______________________________________                                    

The resulting polyimide had the following properties:

    ______________________________________                                        Inherent viscosity   0.491 dl/g                                               Tg(°C.)       261                                                      Tc(°C.)       No                                                       TM(°C.)       No                                                       Crystallinity        x                                                        HDT(°C.)      245                                                      5% Loss Temp. (°C.)                                                                         555                                                      Melt initiation Temp.                                                                              327                                                      Melt viscosity       42000 (380°C.)                                    ______________________________________                                    

EXAMPLE 22

Into the same reaction vessel as described in Example 1, 1.9872 kg (5.4mole) of 4,4'-bis (3-aminophenoxy)biphenyl, 0.175 kg (0.6 moles) of1,4-bis(4-aminophenoxy)benzene, 1.2426 kg (5.7 moles) of pyromelliticdianhydride, 0.0888 kg (0.6 moles) of phthalic anhydride and 13.4 kg ofcresylic acid were charged. The same procedures as described in Example1 were carried out and 3.2 kg of yellow polyimide powder were obtained.The yield was 98%. The polyimide powder had an inherent viscosity of0.51 dl/g and a glass transition temperature of 258° C. Tc and Tm werenot observed. Melt viscosity was 13,000 poise at 380° C.

EXAMPLE 23

Into the same reaction vessel as described in Example 1, 1.9872 kg (5.4mole) of 4,4'-bis (3-aminophenoxy)biphenyl, 0.300 kg (0.06 moles) of1,4-bis[4-(3-aminophenoxy)benzoyl]benzene, 1.2426 kg (5.7 moles) ofpyromellitic dianhydride, 0.0888 kg (0.6 moles) of phthalic anhydrideand 13.4 kg of cresylic acid were charged.

The same procedures as described in Example 1 were carried out and 3.35kg of yellow polyimide powder were obtained. The yield was 98.5%. Thepolyimide powder had an inherent viscosity of 0.50 dl/g and a glasstransition temperature of 257° C. Tc and Tm were not observed. Meltviscosity was 12,100 poise at 380° C.

Synthesis Example 1 of Polyimide of the Second Aspect of the Invention

A reaction vessel equipped with a stirrer, reflux condenser and nitrogeninlet tube was charged with 4.0 kg (10 moles) of4,4'-bis(3-aminophenoxy)diphenyl sulfide and 34.8 kg ofN,N-dimethylacetamide. To the mixture was added 2.14 kg (9.8 moles) ofpyromellitic dianhydride in a nitrogen atmosphere in a manner so as tomaintain the mixture at about room temperature and the mixture isstirred for about 20 hours at the room temperature.

To the polyamic acid solution obtained, 2.02 kg (20 moles) oftriethylamine and 2.55 kg (25 moles) of acetic anhydride were addeddropwise in a nitrogen atmosphere at the room temperature. The reactionmixture was stirred for about 20 hours to obtain a light yellow slurry.The slurry was filtered, washed with methanol, filtered again and driedat 180° C. for 8 hours under reduced pressure to obtain 5.64 kg (about97.5% yield) of polyimide powder. The inherent viscosity of thepolyimide powder was 0.85 dl/g.

The inherent viscosity was measured at 35° C. after dissolving 0.5 g ofthe polyimide powder in 100 ml of a solvent (a mixture of p-chlorophenoland phenol in a ratio of 90:10) at elevated temperatures.

EXAMPLES 24-27 AND COMPARATIVE EXAMPLES 10-11

The polyimide powder obtained in Synthesis Example 1 was dry blendedwith aromatic polyetherimide powder (Trade Mark; ULTEM 1000, a productof General Electric Co. in U.S.A.) in the ratio of Table 5 andpelletized by extruding at 370°-400° C. with a twin screw extruder. Thepellets thus obtained was fed to an injection molding machine having acylinder temperature of 360°-390° C., injection pressure of 1000 kg/cm²and mold temperature of 100°-150° C. The injection molded specimens weremeasured with respect to their mechanical and abrasion properties. Thepellets obtained were fed to a Brabender type viscometer (Trade Mark;Laboplastomill, a product of Toyo Seiki Seisakusho Ltd.). Melt torquewas measured under the conditions of 385° C. in temperature and 50 rpmin rotor revolution. Results obtained are illustrated in Table 5.Thermal properties were measured with a rectangular parallelopipedspecimen having dimensions of 6×3×3 mm. The glass transition temperatureTg was measured with a thermo-mechanical analysis instrument (TradeMark; TM-30, a product of Shimadzu Seisakusho Ltd.). Heat distortiontemperature was examined with a load of 18.6 kg/cm² in accordance withASTM D-648. As to the mechanical property, impact strength with a 1/8inch notch was tested in accordance with ASTM D-256. As to the abrasionproperty, coefficient of abrasion was measured with a thrust abraderunder such conditions that sliding velocity is 128 m/min and surfacepressure is 0.78 kg/cm². The same testing methods as in Examples 24-27were used in Examples 28-41 and Comparative Examples 10-11.

                  TABLE 5                                                         ______________________________________                                                                 Comparative                                                   Example         example                                                       24    25      26     27   10    11                                   ______________________________________                                        Polymer (wt. %)                                                               Aromatic poly-                                                                           10      50      70   90   100   98                                 etherimide                                                                    (ULTEM 1000)                                                                  Polyimide  90      50      30   10   0     2                                  (Polymer                                                                      obtained in                                                                   Synthesis                                                                     Example 1)                                                                    Property                                                                      Glass transi-                                                                            235     232     227  220  215   217                                tion tempera-                                                                 ture (°C.)                                                             Heat distor-                                                                             219     215     210  202  193   195                                tion tempera-                                                                 ture (°C.)                                                             Izod impact                                                                              20.7    18.5    16.0 14.0 4.7   4.7                                strength                                                                      (notched)                                                                     (kg · cm/cm)                                                         Abrasion Co-                                                                  efficient                                                                     (× 10.sup.-8 cm.sup.3 /                                                 kg · m)                                                               23° C.                                                                           72      80      88   98   201   200                                250° C.                                                                           322     511     595  630  1785  1800                               Friction co-                                                                  efficient                                                                      23° C.                                                                           0.25    0.25    0.25 0.25 0.25  0.25                               250° C.                                                                           0.24    0.26    0.27 0.30 0.40< 0.40<                              Melt torque                                                                              130     115     88   80   78    77                                 (kg · cm)                                                                       -132    -118    -93  -83  -80   -80                                ______________________________________                                    

Synthesis Examples 2-5

The same procedures as Synthesis Example 1 were carried out except thatvarious diamines were used in place of 4,4'-bis(3-aminophenoxy)diphenylsulfide, various tetracarboxylic acid dianhydrides were used in place ofpyromellitic dianhydride, and the amounts of diamines,N,N-dimethylacetamide and tetracarboxylic acid dianhydrides werechanged.

As a result, various kinds of polyimide powder were obtained. Table 6illustrates synthetic conditions of polyimide and inherent viscositiesof polyimide obtained under respective conditions of synthesis.

                                      TABLE 6                                     __________________________________________________________________________                                        Polyimide                                                   N,N-              inherent                                  Synthesis         Dimethyl                                                                            Tetracarboxylic acid                                                                      viscosity                                 example                                                                            Diamine      acetamide                                                                           dianhydride (dl/g)                                    __________________________________________________________________________    2    4,4'-Bis(3-aminophenoxy)                                                                   38.8 kg                                                                             3,3',4,4'-benzophenone-                                                                   0.62                                           biphenyl           tetracarboxylic acid                                       3.68 kg (10 moles) dianhydride                                                                   3.16 kg (9.85 moles)                                  3    4,4'-Bis(3-aminophenoxy)                                                                   33.0 kg                                                                             Pyromellitic                                                                              0.70                                           biphenyl           dianhydride                                                3.68 kg (10 moles) 2.125 kg (9.75 moles)                                 4    4,4'-Bis(3-aminophenoxy)                                                                   33.7 kg                                                                             Pyromellitic                                                                              0.78                                           diphenyl sulfide   dianhydride                                                3.8 kg (9 moles)   2.11 kg (9.7 moles)                                        4,4'-Diaminodiphenyl                                                          ether                                                                         0.202 kg (1 mole)                                                        5    4,4'-Bis(3-aminophenoxy)                                                                   32.3 kg                                                                             Pyromellitic                                                                              0.72                                           biphenyl           dianhydride                                                3.5 kg (9.5 moles) 2.10 kg (9.65 moles)                                       4,4'-Diaminodiphenyl ether                                                    0.101 kg (0.5 mole)                                                      __________________________________________________________________________

EXAMPLES 28-38 AND COMPARATIVE EXAMPLES 12-14

The polyimide powder obtained in Synthesis examples 2-5 was kneaded witharomatic polyetherimide powder (Trade Mark; ULTEM 1000, a product ofGeneral Electric Co. in U.S.A.) by fusing in various mixing ratios toobtain uniformly blended pellets. The pellets obtained were molded inthe same conditions as described in Example 23. Thermal, mechanical andabrasive properties were measured on the molded specimens and areillustrated in Tables 8-11 Besides the correspondence of polyimide usedto examples and comparative examples is shown in Table 7.

                  TABLE 7                                                         ______________________________________                                                  Example      Comparative                                                                              Table                                       Polyimide No.          example No.                                                                              No.                                         ______________________________________                                        Synthesis 28-30        12          8                                          example 2                                                                     Synthesis 31-34        13          9                                          example 3                                                                     Synthesis 35-36        --         10                                          example 4                                                                     Synthesis 37-38        14         11                                          example 5                                                                     Synthesis 39-41        --         12                                          example 3                                                                     ______________________________________                                    

                  TABLE 8                                                         ______________________________________                                                                  Comparative                                                   Example         example                                                       28    29       30       12                                          ______________________________________                                        Polymer (wt. %)                                                               Aromatic    50      70       90     97                                        polyetherimide                                                                (ULTEM 1000)                                                                  Polyamide (Polymer                                                                        50      30       10     3                                         obtained in                                                                   Synthesis                                                                     Example 2)                                                                    Property                                                                      Glass transition                                                                          231     227      221    218                                       temperature (°C.)                                                      Heat distortion                                                                           214     210      204    199                                       temperature (°C.)                                                      Izod impact strength                                                                      15.0    13.5     11.2   5.0                                       (notched)                                                                     (kg · cm/cm)                                                         Abrasion Coefficient                                                          (× 10.sup.-8 cm.sup.3 /                                                 kg · m)                                                               23° C.                                                                            78      87       96     198                                       250° C.                                                                            499     587      600    1790                                      Friction coefficient                                                           23° C.                                                                            0.24    0.24     0.25   0.25                                      250° C.                                                                            0.24    0.26     0.31   0.40<                                     Melt torque 114     87       79     75                                        (kg · cm)                                                                        -118    -92      -83    -78                                       ______________________________________                                    

                  TABLE 9                                                         ______________________________________                                                                    Compar-                                                                       ative                                                       Example           example                                                     31    32      33      34    13                                      ______________________________________                                        Polymer (wt. %)                                                               Aromatic    10      50      70    90    98                                    polyetherimide                                                                (ULTEM 1000)                                                                  Polyimide (Polymer                                                                        90      50      30    10    2                                     obtained in                                                                   Synthesis                                                                     Example 3)                                                                    Property                                                                      Glass transition                                                                          255     253     249   236   219                                   temperature (°C.)                                                      Heat distortion                                                                           238     235     231   216   199                                   temperature (°C.)                                                      Izod impact strength                                                                      18.2    16.1    14.0  10.0  4.7                                   (notched)                                                                     (kg · cm/cm)                                                         Abrasion Coefficient                                                          (× 10.sup.-8 cm.sup.3 /                                                 kg · m)                                                               23° C.                                                                            50      71      81    92    200                                   250° C.                                                                            302     490     570   820   1787                                  Friction coefficient                                                           23° C.                                                                            0.21    0.22    0.24  0.25  0.25                                  250° C.                                                                            0.21    0.24    0.25  0.29  0.40<                                 Melt torque 132     115     89    81    76                                    (kg· cm)                                                                         -135    -117    -91   -83   -78                                   ______________________________________                                    

                  TABLE 10                                                        ______________________________________                                                         Example                                                                       35      36                                                   ______________________________________                                        Polymer (wt. %)                                                               Aromatic polyetherimide                                                                          10        90                                               (ULTEM 1000)                                                                  Polyimide (Polymer 90        10                                               obtained in Synthesis                                                         Example 4)                                                                    Property                                                                      Glass transition   285       247                                              temperature (°C.)                                                      Heat distortion    265       222                                              temperature (°C.)                                                      Izod impact strength                                                                             20        15                                               (notched) (kg · cm/cm)                                               Abrasion Coefficient                                                          (×10.sup.-8 cm.sup.3 /kg · m)                                   23° C.     68        96                                               250° C.     329       615                                              Friction coefficient                                                           23° C.     0.24      0.24                                             250° C.     0.22      0.31                                             Melt torque        131       80                                               (kg · cm) -133      -84                                              ______________________________________                                    

                  TABLE 11                                                        ______________________________________                                                                  Comparative                                                      Example      example                                                          37      38       14                                              ______________________________________                                        Polymer (wt. %)                                                               Aromatic polyetherimide                                                                      25        90       98                                          (ULTEM 1000)                                                                  Polyimide (Polymer                                                                           75        10       2                                           obtained in Synthesis                                                         Example 5)                                                                    Property                                                                      Glass transition                                                                             290       255      220                                         temperature (°C.)                                                      Heat distortion                                                                              274       235      200                                         temperature (°C.)                                                      Izod impact strength                                                                         17        12       4.6                                         (notched) (kg · cm/cm)                                               Abrasion Coefficient                                                          (×10.sup.-8 cm.sup.3 /kg · m)                                   23° C. 48        78       196                                         250° C. 390       592      1305                                        Friction coefficient                                                           23° C. 0.21      0.23     0.24                                        250° C. 0.22      0.27     0.40<                                       Melt torque    121       82       77                                          (kg · cm)                                                                           -127      -85      -80                                         ______________________________________                                    

EXAMPLES 39-41

The polyimide powder obtained in Synthesis example 3 was kneaded witharomatic polyetherimide powder (Trade Mark; ULTEM 6000, a product ofGeneral Electric Co. in U.S.A.) by fusing in various mixing ratios toobtain uniformly blended pellets. The pellets obtained were molded inthe same conditions as described in Example 24. Thermal and mechanicalproperties were measured on the molded specimens and are illustrated inTable 12.

                  TABLE 12                                                        ______________________________________                                                       Example                                                                       39      40      41                                             ______________________________________                                        Polymer (wt. %)                                                               Aromatic polyetherimide                                                                        10        50      90                                         (ULTEM 6000)                                                                  Polyimide (Polymer                                                                             90        50      10                                         obtained in Synthesis                                                         Example 3)                                                                    Property                                                                      Glass transition 258       256     242                                        temperature (°C.)                                                      Heat distortion  238       236     221                                        temperature (°C.)                                                      Izod impact strength                                                                           18.3      17.0    12.0                                       (notched) (kg · cm/cm)                                               ______________________________________                                    

Synthesis Example 1 of the Polyimide of the Third Aspect of theInvention

A reaction vessel equipped with a stirrer, reflux condenser and nitrogeninlet tube was charged with 4.0 kg (10 moles) ofbis[4-(3-aminophenoxy)phenyl]sulfide and 34.8 kg ofN,N-dimethylacetamide. To the mixture was added 2.14 kg (9.8 moles) ofpyromellitic dianhydride by portions in a nitrogen atmosphere at theroom temperature and at a rate to avoid a large temperature rise of thesolution and stirred for 20 hours at the room temperature.

To the resultant polyamic acid solution, 2.02 kg (20 moles) oftriethylamine and 2.55 kg (25 moles) of acetic anhydride were addeddropwise in nitrogen atmosphere at the room temperature and stirred for20 hours at the room temperature to obtain a light yellow slurry. Theslurry was filtered to obtain light yellow polyimide powder. Thepolyimide powder was formed into a sludge with methanol, filtered anddried at 180° C. for 8 hours under reduced pressure to obtain 5.63 kg(about 97.5% yield) of polyimide powder. The inherent viscosity of thepolyimide powder was 0.85 dl/g. The inherent viscosity was measured at35° C. after dissolving 0.5 g of the polyimide powder in 100 ml of asolvent (a mixture of p-chlorophenol and phenol in a ratio of 90:10 byweight) at elevated temperatures and cooling the resulting solution.

Synthesis Examples 2-5

The same procedures as Synthesis Example 1 were carried out. However,raw materials were changed as follows. Various diamines were used inplace of [4-(3-aminophenoxy)phenyl]sulfide and various tetracarboxylicacid dianhydrides were used in place of pyromellitic dianhydride. Theamounts of diamines, N,N-dimethylacetamide and tetracarboxylic aciddianhydride were varied to obtain various polyimide powders. Table 13illustrates conditions for the synthesis of the polyimide resins.

                                      TABLE 13                                    __________________________________________________________________________                           N,N-dimethyl                                                                         Tetracarboxylic acid                                                                            Inherent                      Synthesis                                                                          Diamine           acetamide                                                                            dianhydride       viscosity                     example                                                                            kg (mole)         kg (mole)                                                                            kg (mole)         (dl/g)                        __________________________________________________________________________    2    4,4'Bis(3-aminophenoxy)biphenyl                                                                 38.8 kg                                                                              3,3',4,4'-Benzophenonetetracarboxylic                                                           0.62                               3.68 kg (10 moles)       dianhydride                                                                   3.16 kg (9.85 moles)                            3    4,4'-Bis(3-aminophenoxy)biphenyl                                                                  33 kg                                                                              Pyromellitic dianhydride                                                                        0.70                               3.68 kg (10 moles)       2.125 kg (9.75 moles)                           4    Bis[4-(3-aminophenoxy)phenyl] sulfide                                                           33.7 kg                                                                              Pyromellitic dianhydride                                                                        0.78                               3.6 kg (9 moles)         2.11 kg (9.7 moles)                                  Bis(4-aminophenyl) ether                                                      0.202 kg (1 mole)                                                        5    4,4'-Bis(3-aminophenoxy)biphenyl                                                                32.3 kg                                                                              Pyromellitic dianhydride                                                                        0.72                               3.5 kg (9.5 moles)       2.10 kg (9.65 moles)                                 Bis(4-aminophenyl) ether                                                      0.101 kg (0.5 mole)                                                      __________________________________________________________________________

Synthesis Example 6

A reaction vessel equipped with a stirrer, reflux condenser and nitrogeninlet tube was charged with 5 kg (10 moles) of1,3-bis[4-(3-aminophenoxy)benzoyl]benzene and 40.5 kg ofN,N-dimethylacetamide. The mixture was cooled to about 0° C. and 2.147kg (9.85 moles) of pyromellitic dianhydride was added in five portionsin a nitrogen atmosphere at a rate to avoid a large temperature rise ofthe solution. Then the temperature of the reaction mixture was raised tothe room temperature and the mixture was stirred for 20 hours at theroom temperature.

To the resultant polyamic acid solution, 2.02 kg (20 moles) oftriethylamine and 2.55 kg (25 moles) of acetic anhydride were addeddropwise in a nitrogen atmosphere at the room temperature and stirredfor 20 hours at the room temperature to obtain a yellow slurry. Theslurry was filtered to obtain light yellow polyimide powder. Thepolyimide powder was formed into a sludge with methanol, filtered anddried at 150° C. for 8 hours under reduced pressure to obtain 6.6 kg(about 97.5% yield) of polyimide as light yellow powder. The glasstransition temperature Tg of the powder was 235° C. in accordance withDSC method.

Besides the inherent viscosity of the powder was 0.86 dl/g.

Synthesis Examples 7-10

The same procedures as Synthesis example 6 were carried out by usingvarious combinations of diamines and tetracarboxylic acid dianhydridesto obtain a variety of polyimides. Table 14 illustrates synthesisconditions, inherent viscosities and glass transition temperatures ofthe polyimide powders.

                                      TABLE 14                                    __________________________________________________________________________                              Tetracarboxylic acid                                                                            Inherent                          Synthesis                                                                          Diamine              dianhydride       viscosity                                                                          Tg                           example                                                                            kg (mole)            kg (mole)         (dl/g)                                                                             (°C.)                 __________________________________________________________________________    7    1,3-bis[4-(3-aminophenoxy)benzoyl]benzene                                                          3,3',4,4'-Benzophenonetetracarboxylic                                                           0.82 227                               4.75 kg (9.5 moles)  dianhydride                                              Bis(4-aminophenyl) ether                                                                           3.16 kg (9.85 moles)                                     0.101 kg (0.5 mole)                                                      8    1,4-Bis[4-(3-aminophenoxy)benzoyl]benzene                                                          3,3',4,4'-Biphenyltetracarboxylic                                                               0.84 230                               5.0 kg (10 moles)    dianhydride                                                                   2.90 kg (9.85 moles)                                9    1,4-Bis[4-(3-aminophenoxy)benzoyl]benzene                                                          Pyromellitic dianhydride                                                                        0.80 248                               2.5 kg (5 moles)     2.14 kg (9.8 moles)                                      4,4'-Bis(3-aminophenoxy)biphenyl                                              1.84 kg (5 moles)                                                        10   1,4-Bis[4-(3-aminophenoxy)benzoyl]benzene                                                          Bis(3,4-dicarboxyphenyl) ether                                                                  0.78 220                               4.25 kg (8.5 moles)  dianhydride                                              Bis(4-aminophenyl) ether                                                                           3.038 kg (9.8 moles)                                     0.303 kg (1.5 moles)                                                     __________________________________________________________________________

EXAMPLES 42-45

The polyimide powder obtained in Synthesis Example 1 was dry blendedwith polyphenylene sulfide powder RYTON P-4 (Trade Mark; a product ofPhillips Petroleum Co.) in various compositions as illustrated in Table15. The mixture was kneaded by fusing at 320°-340° C. in an extruderhaving 40 mm aperture and a screw of 3.0/1 compression ratio, andextruded to obtain uniform pellets. The pellets thus obtained wasinjection molded at an injection temperature of 350°-390° C. and a moldtemperature of 150° C. The physical and thermal properties of the moldedproduct were measured and the results are illustrated in Table 15. InTable 15, tensile strength and elongation at break, flexural strengthand flexural modulus, izod impact strength, and heat distortiontemperature were respectively measured in accordance with ASTM D-638,D-790, D-256 and D-648.

Besides Table 15 also illustrates minimum injection pressure whichindicates melt flowability. Lower minimum injection pressure resultsfrom better melt flowability.

Comparative Example 15

The same procedures as Examples 42-45 were carried out by using acomposition outside the scope of this invention. The physical andthermal properties of molded specimens were measured and the results areillustrated in Table 15.

                                      TABLE 15                                    __________________________________________________________________________    Example         Poly-                            Izod   Heat                  or              phenylene                                                                            Minimum                   impact distortion            Compar-                                                                            Polyimide  sulfide                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                             Flexural                                                                           Flexural                                                                           strength                                                                             temperature           ative                                                                              Synthesis  RYTON P-4                                                                            pressure                                                                           strength                                                                           tion  strength                                                                           modulus                                                                            (notched)                                                                            (°C.)          example                                                                            example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)   (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg cm/cm)                                                                           (18.6                 __________________________________________________________________________                                                            kg/cm.sup.2)          Ex. 42                                                                             1    98     2     480  1,650                                                                              60    2,800                                                                              36,300                                                                             21.0   215                   Ex. 43                                                                             1    85    15     260  1,640                                                                              55    2,800                                                                              38,000                                                                             20.6   214                   Ex. 44                                                                             1    75    25     190  1,600                                                                              45    2,740                                                                              40,000                                                                             19.9   212                   Ex. 45                                                                             1    50    50     *    1,520                                                                              33    2,560                                                                              41,200                                                                             18.4   200                   Comp. 15                                                                           1    100    0     550  1,650                                                                              60    2,800                                                                              36,300                                                                             21.0   215                   __________________________________________________________________________     *Lower than detection limit of 40 kg/cm.sup.2.                           

EXAMPLES 46-55 AND COMPARATIVE EXAMPLES 16-19

The procedures of Examples 42-45 were repeated by using the polyimidepowder obtained in Synthesis Examples 2-5 to give uniformly blendedpellets. The pellets were injection molded. Physical and thermalproperties were measured on the molded specimens. The results on bothwithin and outside the scope of this invention are illustrated in Tables16-17 as Examples 46-55 and Comparative Examples 16-19, respectively.

                                      TABLE 16                                    __________________________________________________________________________    Example         Poly-                            Izod   Heat                  or              phenylene                                                                            Minimum                   impact distortion            Compar-                                                                            Polyimide  sulfide                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                             Flexural                                                                           Flexural                                                                           strength                                                                             temperature           ative                                                                              Synthesis  RYTON P-4                                                                            pressure                                                                           strength                                                                           tion  strength                                                                           modulus                                                                            (notched)                                                                            (°C.)          example                                                                            example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)   (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg cm/cm)                                                                           (18.6                 __________________________________________________________________________                                                            kg/cm.sup.2)          Ex. 46                                                                             2    95     5     420  1,350                                                                              39    1,800                                                                              36,500                                                                             15.7   210                   Ex. 47                                                                             2    75    25     160  1,340                                                                              38    1,800                                                                              39,800                                                                             15.6   209                   Ex. 48                                                                             2    50    50     *    1,270                                                                              35    1,740                                                                              41,100                                                                             15.0   208                   Comp. 16                                                                           2    100    0     580  1,350                                                                              40    1,800                                                                              36,000                                                                             16.0   210                   Ex. 49                                                                             3    95     5     560  1,150                                                                              100   1,530                                                                              34,000                                                                             18.0   233                   Ex. 50                                                                             3    75    25     230  1,100                                                                              85    1,500                                                                              38,600                                                                             17.8   228                   Ex. 51                                                                             3    50    50     *      990                                                                              60    1,500                                                                              41,200                                                                             16.2   216                   Comp. 17                                                                           3    100    0     650  1,150                                                                              100   1,530                                                                              32,400                                                                             18.3   235                   __________________________________________________________________________     *Lower than detection limit of 40 kg/cm.sup.2.                           

                                      TABLE 17                                    __________________________________________________________________________    Example         Poly-                            Izod   Heat                  or              phenylene                                                                            Minimum                   impact distortion            Compar-                                                                            Polyimide  sulfide                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                             Flexural                                                                           Flexural                                                                           strength                                                                             temperature           ative                                                                              Synthesis  RYTON P-4                                                                            pressure                                                                           strength                                                                           tion  strength                                                                           modulus                                                                            (notched)                                                                            (°C.)          example                                                                            example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)   (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg cm/cm)                                                                           (18.6                 __________________________________________________________________________                                                            kg/cm.sup.2)          Ex. 52                                                                             4    95    5      570  2,100                                                                              78    3,000                                                                              36,500                                                                             16.8   257                   Ex. 53                                                                             4    75    25     230  2,000                                                                              65    2,950                                                                              40,000                                                                             16     252                   Comp. 18                                                                           4    100   0      650  2,100                                                                              80    3,000                                                                              35,000                                                                             17.0   260                   Ex. 54                                                                             5    95    5      750  1,650                                                                              85    1,800                                                                              34,500                                                                             13.8   272                   Ex. 55                                                                             5    50    50     140  1,530                                                                              60    1,750                                                                              41,300                                                                             11.5   256                   Comp. 19                                                                           5    100   0      850  1,700                                                                              90    1,800                                                                              33,000                                                                             14.0   275                   __________________________________________________________________________

EXAMPLES 56-58

The polyimide powder obtained in Synthesis Example 6 was dry blendedwith polyphenylene sulfide RYTON P-4 in various compositions asillustrated in Table 18. The mixture was pelletized by extruding at270°-310° C. with a twin screw extruder.

The pellets obtained were injection molded at the injection temperatureof 280°-320° C. and mold temperature of 150° C. Physical and thermalproperties of molded specimens were measured. Results are illustrated inTable 18.

Comparative Example 20

The same procedures as Examples 42-44 were carried out by using acomposition outside the scope of this invention. The physical andthermal properties of molded specimens were measured and the results areillustrated in Table 18.

                                      TABLE 18                                    __________________________________________________________________________    Example         Poly-                            Izod   Heat                  or              phenylene                                                                            Minimum                   impact distortion            Compar-                                                                            Polyimide  sulfide                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                             Flexural                                                                           Flexural                                                                           strength                                                                             temperature           ative                                                                              Synthesis  RYTON P-4                                                                            pressure                                                                           strength                                                                           tion  strength                                                                           modulus                                                                            (notched)                                                                            (°C.)          example                                                                            example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)   (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg cm/cm)                                                                           (18.6                 __________________________________________________________________________                                                            kg/cm.sup.2)          Ex. 56                                                                             6    95     5     320  1,590                                                                              70    1,960                                                                              38,000                                                                             16.4   220                   Ex. 57                                                                             6    75    25     200  1,560                                                                              65    1,900                                                                              40,200                                                                             15.5   217                   Ex. 58                                                                             6    50    50     *    1,450                                                                              50    1,820                                                                              41,800                                                                             13.5   209                   Comp. 20                                                                           6    100    0     520  1,600                                                                              70    1,960                                                                              37,500                                                                             16.5   220                   __________________________________________________________________________     *Lower than detection limit of 40 kg/cm.sup.2.                           

EXAMPLES 59-67 AND COMPARATIVE EXAMPLES 21-24

The procedures of Examples 56-58 were repeated by using the polyimidepowder obtained in Synthesis Examples 7-10 to give uniformly blendedpellets. The pellets were injection molded. Physical and thermalproperties were measured on the molded specimens. The results on bothwithin and outside the scope of this invention are illustrated in Tables19-20 as Examples 59-67 and Comparative examples 21-24 respectively.

                                      TABLE 19                                    __________________________________________________________________________    Example         Poly-                            Izod   Heat                  or              phenylene                                                                            Minimum                   impact distortion            Compar-                                                                            Polyimide  sulfide                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                             Flexural                                                                           Flexural                                                                           strength                                                                             temperature           ative                                                                              Synthesis  RYTON P-4                                                                            pressure                                                                           strength                                                                           tion  strength                                                                           modulus                                                                            (notched)                                                                            (°C.)          example                                                                            example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)   (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg cm/cm)                                                                           (18.6                 __________________________________________________________________________                                                            kg/cm.sup.2)          Ex. 59                                                                             7    95     5     340  1,850                                                                              68    1,980                                                                              38,000                                                                             15.5   204                   Ex. 60                                                                             7    50    50     *    1,770                                                                              62    1,930                                                                              41,800                                                                             13.0   195                   Comp. 21                                                                           7    100    0     560  1,850                                                                              68    1,980                                                                              38,000                                                                             15.5   204                   Ex. 61                                                                             8    95     5     300  1,390                                                                              60    1,700                                                                              35,800                                                                             12.3   210                   Ex. 62                                                                             8    50    50     *    1,300                                                                              50    1,650                                                                              41,400                                                                             10.5   198                   Comp. 22                                                                           8    100    0     510  1,400                                                                              60    1,700                                                                              34,500                                                                             12.5   210                   Ex. 63                                                                             9    90    10     360  1,490                                                                              83    1,750                                                                              36,100                                                                             17.0   231                   Ex. 64                                                                             9    50    50     *    1,400                                                                              60    1,690                                                                              41,000                                                                             13.5   222                   Comp. 23                                                                           9    100    0     620  1,500                                                                              85    1,750                                                                              35,200                                                                             17.5   231                   __________________________________________________________________________     *Lower than detection limit of 40 kg/cm.sup.2.                           

                                      TABLE 20                                    __________________________________________________________________________    Example          Poly-                           Izod  Heat                   or               phenylene                                                                            Minimum                  impact                                                                              distortion             Compara-                                                                            Polyimide  sulfide                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                            Flexural                                                                           Flexural                                                                           strength                                                                            temperature            tive  Synthesis  RYTON P-4                                                                            pressure                                                                           strength                                                                           tion strength                                                                           modulus                                                                            (notched)                                                                           (°C.)           example                                                                             example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg cm/cm)                                                                          (18.6                  __________________________________________________________________________                                                           kg/cm.sup.2)           Ex. 65                                                                              10   95    5      360  1,350                                                                              64   1,460                                                                              31,400                                                                             11.5  201                    Ex. 66                                                                              10   85    15     240  1,340                                                                              62   1,460                                                                              34,000                                                                             11.0  199                    Ex. 67                                                                              10   75    25     150  1,330                                                                              59   1,440                                                                              36,000                                                                             10.0  195                    Comp. 24                                                                            10   100   0      580  1,350                                                                              65   1,460                                                                              30,000                                                                             11.5  201                    __________________________________________________________________________

EXAMPLES 68-71

The polyimide powder obtained in Synthesis Example 1 was dry blendedwith aromatic polysulfone powder VICTREX PES 3600P (Trade Mark; aproduct of Imperial Chemical Industry) in various compositions asillustrated in Table 21. The mixture was kneaded by fusing at 330°-360°C. in an extruder having 40 mm aperture and a screw of 3.0/1 compressionratio, and extruded to obtain uniform pellets. The pellets thus obtainedwere injection molded at an injection temperature of 360° C. and a moldtemperature of 180° C. The physical and thermal properties of the moldedproduct were measured and the results are illustrated in Table 21.

In Table 21, the glass transition temperature Tg which was measured inaccordance with TMA penetration method is also illustrated.

Comparative Example 25

The same procedures as Examples 68-71 were carried out by using acomposition outside the scope of this invention. The physical andthermal properties of molded specimens were measured and the results areillustrated in Table 21.

                                      TABLE 21                                    __________________________________________________________________________                                                     Izod Heat                    Example          Aromatic                        impact                                                                             distortion              or               Polysulfone                                                                          Minimum                  strength                                                                           temper-                 Compara-                                                                            Polyimide  VICTREX                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                            Flexural                                                                           Flexural                                                                           (notched)                                                                          ature                   tive  Synthesis  PES 3600P                                                                            pressure                                                                           strength                                                                           tion strength                                                                           modulus                                                                            (kg  (°C.)                                                                        Tg8.6             example                                                                             example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      cm/cm)                                                                             kg/cm.sup.2)                                                                        (°C.)      __________________________________________________________________________    Ex. 68                                                                              1    95    5      500  1,650                                                                              60   2,800                                                                              36,300                                                                             21.0 215   235               Ex. 69                                                                              1    85    15     450  1,650                                                                              60   2,800                                                                              36,300                                                                             21.0 215   235               Ex. 70                                                                              1    75    25     380  1,600                                                                              60   2,750                                                                              36,000                                                                             20.2 213   234               Ex. 71                                                                              1    50    50     320  1,480                                                                              60   2,550                                                                              34,500                                                                             19.0 211   231               Comp. 25                                                                            1    100   0      550  1,650                                                                              60   2,800                                                                              36,300                                                                             21.0 215   235               __________________________________________________________________________

EXAMPLES 72-74 AND COMPARATIVE EXAMPLE 26

The polyimide powder obtained in Synthesis Example 2 was dry blendedwith aromatic polysulfone VICTREX PES 3600P in the compositionsillustrated in Table 22 and pelletized by the same procedures asExamples 67-70 at 320°-360° C. The pellets obtained were injectionmolded at 380° C. with a mold temperature of 190° C. Physical andthermal properties of molded specimens were measured. Results areillustrated in Table 22.

                                      TABLE 22                                    __________________________________________________________________________                                                     Izod Heat                    Example          Aromatic                        impact                                                                             distortion              or               Polysulfone                                                                          Minimum                  strength                                                                           temper-                 Compara-                                                                            Polyimide  VICTREX                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                            Flexural                                                                           Flexural                                                                           (notched)                                                                          ature                   tive  Synthesis  PES 3600P                                                                            pressure                                                                           strength                                                                           tion strength                                                                           modulus                                                                            (kg  (°C.)                                                                        Tg8.6             example                                                                             example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      cm/cm)                                                                             kg/cm.sup.2)                                                                        (°C.)      __________________________________________________________________________    Ex. 72                                                                              2    95    5      465  1,350                                                                              40   1,800                                                                              36,000                                                                             16.0 210   235               Ex. 73                                                                              2    75    25     395  1,300                                                                              45   1,800                                                                              35,000                                                                             15.0 207   233               Ex. 74                                                                              2    50    50     335  1,200                                                                              50   1,750                                                                              33,500                                                                             13.5 205   230               Comp. 26                                                                            2    100   0      580  1,350                                                                              40   1,800                                                                              36,000                                                                             16.0 210   235               __________________________________________________________________________

EXAMPLES 75-77 AND COMPARATIVE EXAMPLE 27

The polyimide powder obtained in Synthesis Example 3 was dry blendedwith aromatic polysulfone powder UDEL POLYSULFONE P-1700 (Trade Mark; aproduct of Union Carbide Corp.) in various compositions as illustratedin Table 23. The mixture was kneaded by fusing at 360°-390° C. in anextruder having 40 mm aperture and a screw of 3.0/1 compression ratio,and extruded to obtain uniform pellets. The pellets thus obtained wasinjection molded at an injection temperature of 390° C. and a moldtemperature of 190° C. The physical and thermal properties of the moldedproduct were measured and the results are illustrated in Table 23.

                                      TABLE 23                                    __________________________________________________________________________                     Aromatic                                                                      Polysulfone                     Izod Heat                    Example          UDEL                            impact                                                                             distortion              or               POLY-  Minimum                  strength                                                                           temper-                 Compara-                                                                            Polyimide  SULFONE                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                            Flexural                                                                           Flexural                                                                           (notched)                                                                          ature                   tive  Synthesis  P-1700 pressure                                                                           strength                                                                           tion strength                                                                           modulus                                                                            (kg  (°C.) (18.6                                                            4     Tg                example                                                                             example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      cm/cm)                                                                             kg/cm.sup.2)                                                                        (°C.)      __________________________________________________________________________    Ex. 75                                                                              3    95    5      520  1,120                                                                              100  1,520                                                                              32,400                                                                             18.3 235   253               Ex. 76                                                                              3    85    15     440  1,100                                                                              100  1,520                                                                              32,400                                                                             17.9 233   250               Ex. 77                                                                              3    50    50     350  1,000                                                                              100  1,460                                                                              32,000                                                                             16.5 202   223               Comp. 27                                                                            3    100   0      650  1,150                                                                              100  1,530                                                                              32,400                                                                             18.3 235   255               __________________________________________________________________________

EXAMPLES 78-80 AND COMPARATIVE EXAMPLE 28

The same procedures as Examples 68-71 were carried out to obtainuniformly blended pellets except that the polyimide powder obtained inSynthesis Example 4 and UDEL POLYSULFONE P-1700 were treated at370°-390° C.

The pellets obtained were injection molded at 390° C. with a moldtemperature of 180° C. Physical and thermal properties of moldedspecimens were measured. Results are illustrated in Table 24.

                                      TABLE 24                                    __________________________________________________________________________                     Aromatic                                                                      Polysulfone                     Izod Heat                    Example          UDEL                            impact                                                                             distortion              or               POLY-  Minimum                  strength                                                                           temper-                 Compara-                                                                            Polyimide  SULFONE                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                            Flexural                                                                           Flexural                                                                           (notched)                                                                          ature                   tive  Synthesis  P-1700 pressure                                                                           strength                                                                           tion strength                                                                           modulus                                                                            (kg  (°C.) (18.6                                                            2     Tg                example                                                                             example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      cm/cm)                                                                             kg/cm.sup.2)                                                                        (°C.)      __________________________________________________________________________    Ex. 78                                                                              4    95    5      600  2,080                                                                              80   3,000                                                                              35,000                                                                             17.0 260   285               Ex. 79                                                                              4    75    25     480  2,000                                                                              80   3,000                                                                              35,000                                                                             16.5 255   280               Ex. 80                                                                              4    50    50     330  1,850                                                                              80   2,800                                                                              34,200                                                                             15.5 252   275               Comp. 28                                                                            4    100   0      650  2,100                                                                              80   3,000                                                                              35,000                                                                             17.0 260   285               __________________________________________________________________________

EXAMPLES 81-83 AND COMPARATIVE EXAMPLE 29

The same procedures as Examples 68-71 were carried out to obtainuniformly blended pellets except that the polyimide powder obtained inSynthesis Example 5 and aromatic polysulfone VICTREX PES 3600P weretreated at 370°-390° C.

The pellets obtained were injection molded at 390° C. with a moldtemperature of 180° C. Physical and thermal properties of moldedspecimens were measured. Results are illustrated in Table 25.

                                      TABLE 25                                    __________________________________________________________________________                                                     Izod Heat                    Example          Aromatic                        impact                                                                             distortion              or               Polysulfone                                                                          Minimum                  strength                                                                           temper-                 Compara-                                                                            Polyimide  VICTREX                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                            Flexural                                                                           Flexural                                                                           (notched)                                                                          ature                   tive  Synthesis  PES 3600P                                                                            pressure                                                                           strength                                                                           tion strength                                                                           modulus                                                                            (kg  (°C.)                                                                        Tg8.6             example                                                                             example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      cm/cm)                                                                             kg/cm.sup.2)                                                                        (°C.)      __________________________________________________________________________    Ex. 81                                                                              5    95    5      800  1,700                                                                              90   1,800                                                                              33,000                                                                             14.0 274   293               Ex. 82                                                                              5    75    25     600  1,660                                                                              90   1,780                                                                              33,000                                                                             12.0 270   289               Ex. 83                                                                              5    50    50     450  1,580                                                                              90   1,700                                                                              31,000                                                                             10.0 261   282               Comp. 29                                                                            5    100   0      850  1,700                                                                              90   1,800                                                                              33,000                                                                             14.0 275   295               __________________________________________________________________________

EXAMPLES 84-86

The polyimide powder obtained in Synthesis Example 6 was dry blendedwith aromatic polysulfone powder UDEL POLYSULFONE P-1700 in variouscompositions as illustrated in Table 26. The mixture was pelletized byextruding at 300°-330° C. with a twin screw extruder.

The pellets obtained were injection molded at the cylinder temperatureof 330°-360° C. and mold temperature of 150° C. Physical and thermalproperties of molded specimens were measured. Results are illustrated inTable 26.

Comparative Example 30

The sample procedures as Examples 84-86 were carried out by using acomposition outside the scope of this invention. The physical andthermal properties of molded specimens were measured and the results areillustrated in Table 26.

                                      TABLE 26                                    __________________________________________________________________________                     Aromatic                                                                      Polysulfone                     Izod Heat                    Example          UDEL                            impact                                                                             distortion              or               POLY-  Minimum                  strength                                                                           temper-                 Compara-                                                                            Polyimide  SULFONE                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                            Flexural                                                                           Flexural                                                                           (notched)                                                                          ature                   tive  Synthesis  P-1700 pressure                                                                           strength                                                                           tion strength                                                                           modulus                                                                            (kg  (°C.) (18.6                                                            .     Tg                example                                                                             example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      cm/cm)                                                                             kg/cm.sup.2)                                                                        (°C.)      __________________________________________________________________________    Ex. 84                                                                              6    95    5      420  1,600                                                                              72   1,960                                                                              37,500                                                                             16.5 219   238               Ex. 85                                                                              6    75    25     310  1,580                                                                              90   1,950                                                                              37,200                                                                             16.0 216   236               Ex. 86                                                                              6    50    50     275  1,500                                                                              98   1,880                                                                              36,100                                                                             14.8 210   230               Comp. 30                                                                            6    100   0      520  1,600                                                                              70   1,960                                                                              37,500                                                                             16.5 220   238               __________________________________________________________________________

EXAMPLES 87-94 AND COMPARATIVE EXAMPLES 31-34

The polyimide powder obtained in Synthesis Examples 7-10 was mixed witharomatic polysulfone. VICTREX PES 3600P and UDEL POLYSULFONE P-1700 areused as aromatic polysulfone. The resulting mixtures having compositionsillustrated in Tables 27-29 were kneaded by fusing in an extruder toobtain uniformly blended pellets.

The pellets above obtained were injection molded with the sameconditions as Examples 84-86. The molded specimens were measured theirphysical and thermal properties. The results obtained are illustrated inTables 27-29.

                                      TABLE 27                                    __________________________________________________________________________                     Aromatic                                                                      Polysulfone                     Izod Heat                    Example          UDEL                            impact                                                                             distortion              or               POLY-  Minimum                  strength                                                                           temper-                 Compara-                                                                            Polyimide  SULFONE                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                            Flexural                                                                           Flexural                                                                           (notched)                                                                          ature                   tive  Synthesis  P-1700 pressure                                                                           strength                                                                           tion strength                                                                           modulus                                                                            (kg  (°C.) (18.6                                                                  Tg                example                                                                             example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      cm/cm)                                                                             kg/cm.sup.2)                                                                        (°C.)      __________________________________________________________________________    Ex. 87                                                                              7    95    5      470  1,850                                                                              72   1,980                                                                              38,000                                                                             15.0 204   228               Ex. 88                                                                              7    50    50     290  1,730                                                                              95   1,850                                                                              36,800                                                                             14.2 202   226               Comp. 31                                                                            7    100   0      560  1,850                                                                              68   1,980                                                                              38,000                                                                             15.5 204   228               __________________________________________________________________________

                                      TABLE 28                                    __________________________________________________________________________                                                     Izod Heat                    Example          Aromatic                        impact                                                                             distortion              or               Polysulfone                                                                          Minimum                  strength                                                                           temper-                 Compara-                                                                            Polyimide  VICTREX                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                            Flexural                                                                           Flexural                                                                           (notched)                                                                          ature                   tive  Synthesis  PES 3600P                                                                            pressure                                                                           strength                                                                           tion strength                                                                           modulus                                                                            (kg  (°C.)                                                                        Tg8.6             example                                                                             example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      cm/cm)                                                                             kg/cm.sup.2)                                                                        (°C.)      __________________________________________________________________________    Ex. 89                                                                              8    90    10     410  1,390                                                                              61   1,700                                                                              34,300                                                                             12.5 210   230               Ex. 90                                                                              8    50    50     300  1,370                                                                              64   1,650                                                                              33,500                                                                             11.5 207   228               Comp. 32                                                                            8    100   0      510  1,400                                                                              60   1,700                                                                              34,500                                                                             12.5 210   230               Ex. 91                                                                              9    95    5      480  1,500                                                                              85   1,740                                                                              35,200                                                                             17.0 231   250               Ex. 92                                                                              9    50    50     310  1,420                                                                              80   1,710                                                                              34,100                                                                             16.0 227   247               Comp. 33                                                                            9    100   0      620  1,500                                                                              85   1,750                                                                              35,200                                                                             17.5 231   250               __________________________________________________________________________

                                      TABLE 29                                    __________________________________________________________________________                     Aromatic                                                                      Polysulfone                     Izod Heat                    Example          UDEL                            impact                                                                             distortion              or               POLY-  Minimum                  strength                                                                           temper-                 Compara-                                                                            Polyimide  SULFONE                                                                              injection                                                                          Tensile                                                                            Elonga-                                                                            Flexural                                                                           Flexural                                                                           (notched)                                                                          ature                   tive  Synthesis  P-1700 pressure                                                                           strength                                                                           tion strength                                                                           modulus                                                                            (kg  (°C.) (18.6                                                                  Tg                example                                                                             example                                                                            (wt. parts)                                                                         (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      cm/cm)                                                                             kg/cm.sup.2)                                                                        (°C.)      __________________________________________________________________________    Ex. 93                                                                              10   95    5      435  1,350                                                                              68   1,460                                                                              30,000                                                                             11.5 201   220               Ex. 94                                                                              10   50    50     260  1,250                                                                              90   1,410                                                                              28,000                                                                             10.0 197   214               Comp. 34                                                                            10   100   0      580  1,350                                                                              65   1,460                                                                              30,000                                                                             11.5 201   220               __________________________________________________________________________

EXAMPLES 95-106

The polyimide powder obtained in Synthesis Examples 6-10 was dry blendedwith the commercially available aromatic polyetherimide ULTEM 1000(Trade Mark; a product of General Electric Co. in U.S.A.) in variouscompositions as illustrated in Tables 30-32. The mixture was pelletizedby extruding at 370°-400° C. with a twin screw extruder.

The pellets obtained were injection molded at the cylinder temperatureof 360°-390° C. and mold temperature of 150° C. Physical and thermalproperties of molded specimens were measured. Results are illustrated inTables 30-32.

Comparative Examples 35-39

The same procedures as Examples 95-106 were carried out by using acomposition outside the scope of this invention. The physical andthermal properties of molded specimens were measured and the results areillustrated in Tables 30-32.

                                      TABLE 30                                    __________________________________________________________________________    Example        Aromatic                          Izod  Heat                   or             polyether-                                                                           Minimum                    impact                                                                              distortion             Compar-                                                                            Polyimide imide  injection                                                                          Tensile                                                                             Elonga-                                                                            Flexural                                                                           Flexural                                                                            strength                                                                            temperature            ative                                                                              Synthesis                                                                           (wt.                                                                              ULTEM-1000                                                                           pressure                                                                           strength                                                                            tion strength                                                                           modulus                                                                             (notched)                                                                           (°C.)           example                                                                            example                                                                             parts)                                                                            (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                       (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                       (kg cm/cm)                                                                          (18.6                  __________________________________________________________________________                                                           kg/cm.sup.2)           Ex. 95                                                                             6     95   5     510  1,580 70   1,950                                                                              37,300                                                                              16.2  219                    Ex. 96                                                                             6     85  15     480  1,560 68   1,930                                                                              37,100                                                                              15.7  218                    Ex. 97                                                                             6     75  25     455  1,530 67   1,900                                                                              36,800                                                                              15.0  217                    Ex. 98                                                                             6     50  50     410  1,430 65   1,800                                                                              36,100                                                                              12.7  212                    Comp. 35                                                                           6     100  0     520  1,600 70   1,960                                                                              37,500                                                                              16.5  220                    __________________________________________________________________________

                                      TABLE 31                                    __________________________________________________________________________    Example        Aromatic                          Izod  Heat                   or             polyether-                                                                           Minimum                    impact                                                                              distortion             Compar-                                                                            Polyimide imide  injection                                                                          Tensile                                                                             Elonga-                                                                            Flexural                                                                           Flexural                                                                            strength                                                                            temperature            ative                                                                              Synthesis                                                                           (wt.                                                                              ULTEM-1000                                                                           pressure                                                                           strength                                                                            tion strength                                                                           modulus                                                                             (notched)                                                                           (°C.)           example                                                                            example                                                                             parts)                                                                            (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                       (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                       (kg cm/cm)                                                                          (18.6                  __________________________________________________________________________                                                           kg/cm.sup.2)           Ex. 99                                                                             7     90  10     510  1,810 67   1,960                                                                              37,700                                                                              15.0  203                    Ex. 100                                                                            7     50  50     415  1,600 63   1,820                                                                              36,500                                                                              12.0  201                    Comp. 36                                                                           7     100  0     560  1,850 68   1,980                                                                              38,000                                                                              15.5  204                    Ex. 101                                                                            8     70  30     435  1,350 60   1,670                                                                              34,300                                                                              11.0  208                    Ex. 102                                                                            8     50  50     405  1,300 60   1,630                                                                              34,000                                                                               9.5  206                    Comp. 37                                                                           8     100  0     510  1,400 60   1,700                                                                              34,500                                                                              12.5  210                    __________________________________________________________________________

                                      TABLE 32                                    __________________________________________________________________________    Example        Aromatic                          Izod  Heat                   or             polyether-                                                                           Minimum                    impact                                                                              distortion             Compar-                                                                            Polyimide imide  injection                                                                          Tensile                                                                             Elonga-                                                                            Flexural                                                                           Flexural                                                                            strength                                                                            temperature            ative                                                                              Synthesis                                                                           (wt.                                                                              ULTEM-1000                                                                           pressure                                                                           strength                                                                            tion strength                                                                           modulus                                                                             (notched)                                                                           (°C.)           example                                                                            example                                                                             parts)                                                                            (wt. parts)                                                                          (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                       (%)  (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                       (kg cm/cm)                                                                          (18.6                  __________________________________________________________________________                                                           kg/cm.sup.2)           Ex. 103                                                                             9    95   5     570  1,490 84   1,750                                                                              35,200                                                                              17.2  231                    Ex. 104                                                                             9    75  25     505  1,450 82   1,710                                                                              35,000                                                                              16.0  226                    Comp. 38                                                                            9    100  0     620  1,500 85   1,750                                                                              35,200                                                                              17.5  231                    Ex. 105                                                                            10    75  25     465  1,310 64   1,470                                                                              30,600                                                                              10.3  200                    Ex. 106                                                                            10    50  50     415  1,270 62   1,470                                                                              31,400                                                                               9.0  200                    Comp. 39                                                                           10    100  0     580  1,350 65   1,460                                                                              30,000                                                                              11.5  201                    __________________________________________________________________________

Synthesis Example 1 of the Polyimide of the Fourth Aspect of theInvention

In a reaction flask filled with a stirrer, a reflux condenser and anitrogen introducing tube were placed 3.66 kg (10 moles) of4,4,-bis(3-aminophenoxy)biphenyl and 52.15 kg of N,N-dimethylacetamide,followed by addition of 2.11 kg (9.7 mols) of pyromellitic dianhydrideat room temperature in nitrogen atmosphere with attention paid toelevation of the temperature of the solution. Then stirring wascontinued at room temperature for about 20 hours.

To this polyamide acid solution, 2.20 kg (20 mols) of triethylamine and3.06 kg (30 mols) of acetic anhydride were dropped at room temperaturein nitrogen atmosphere. After 20 hours of stirring, there was produced ayellow slurry, which was filtered off to yield a light yellow polyimidepowder. To the resultant powder, methanol was added to produce a sludge,which was filtered off and dried at 180° C. under reduced pressure for 8hours to yield 5.36 kg of polyimide powder.

The thus-obtained polyimide powder had a inherent viscosity of 0.50dl/g, as determined in the procedure: polyimide powder (0.5 g) wasdissolved in 100 ml of solvent with heating, then allowed to cool to 35°C. and measured with a mixture of p-chlorophenol and phenol (90:10parts/parts by weight) as solvent.

The glass transition temperature of the powder was 256° C. as measuredaccording to DSC and the thermal decomposition temperature 5% at 560° C.as measured according to DTA-TG.

Synthesis Examples 2 to 4

With different diamines and different tetracarboxylic dianhydrides invarying combination powders of various polyimides were obtained in thesame process as described in Synthesis Example 1.

Table 33 gives a summary of Synthesis Examples 1 through 4 whichincludes synthesis conditions of polyimide resins, and inherentviscosities of the produced polyimide powders. It includes theconditions for preparation in Synthesis Example 1 and the physicalproperties of the produced polyimide powder.

                                      TABLE 33                                    __________________________________________________________________________                        Tetracarboxylic                                                                            Inherent                                            Diamine      dianhydride  viscosity                                           Name, kg (mol)                                                                             Name, kg (mol)                                                                             (dl/g)                                       __________________________________________________________________________    Synthesis 1                                                                          4,4'-bis(3-amino-                                                                          Pyromellitic dianhydride                                                                   0.50                                                phenoxy)biphenyl                                                                           2.11 kg (9.7 mol)                                                3,68 kg (10 mol)                                                       Synthesis 2                                                                          4,4'-bis(3-amino-                                                                          4,4'-(p-phenylene-                                                                         0.52                                                phenoxy)biphenyl                                                                           dioxy)diphthalic                                                 3.68 kg (10 mol)                                                                           dianhydride                                                                   3.92 kg (9.75 mol)                                        Synthesis 3                                                                          Bis[4-(3-amino-                                                                            Pyromellitic dianhydride                                                                   0.49                                                phenoxy)phenyl]sulfide                                                                     2.11 kg (9.7 mol)                                                4.0 kg (10 mol)                                                        Synthesis 4                                                                          Bis[4-(3-amino-                                                                            3,3',4,4'-biphenyl                                                                         0.50                                                phenoxy)phenyl]sulfide                                                                     tetracarboxylic                                                  4.0 kg (10 mol)                                                                            dianhydride                                                                   2.87 kg (9.7 mol)                                         __________________________________________________________________________

Synthesis Example 5

In a reaction flask, which is similar to that used in Synthesis Example1, were placed 5 kg (10 mols) of1,3-bis[4-(3-aminophenoxy)benzoyl]benzene and 40.1 kg ofN,N-dimethylacetoamide, and cooled to about 0° C., to which 5 portions(a total of 2,082 kg (9.55 mols)) of pyromellitic dianhydride were addedin sequence in nitrogen atmosphere with attention paid to elevation ofthe temperature of the solution. Stirring was continued for about 2hours. Subsequently the solution was cooled to room temperature,followed by about 20 hours' further stirring in nitrogen atmosphere.

To this polyamide acid solution 2,20 kg (20 mols) of triethylamine and2.55 kg (25 mols) acetic anhydride were dripped at room temperature innitrogen atmosphere. After 20 hours' stirring, there was produced ayellow slurry, which was filtered off to yield a light yellow polyimidepowder. To the resultant powder, methanol was added to produce a sludge,which was filtered off and dried at 150° C. under reduced pressure for 8hours to obtain 6.5 kg (yield: about 97.5%) of light yellow polyimidepowder. The glass transition temperature of this powder was 235° C. asmeasured according DSC, and the inherent viscosity was 0.53 dl/g.

Synthesis Examples 6 to 9

With different diamines and different tetracarboxylic acid dianhydridesin varying combinations, powders of various polyimides were obtained inthe same process as described in Synthesis Example 5. Table 34 gives asummary of Synthesis Examples 5 through 9 which includes synthesisconditions and inherent viscosities of the obtained polyimide powders.

                                      TABLE 34                                    __________________________________________________________________________                        Tetracarboxylic                                                                            Inherent                                            Diamine      dianhydride  viscosity                                           Name, kg (mol)                                                                             Name, kg (mol)                                                                             (dl/g)                                       __________________________________________________________________________    Synthesis 5                                                                          1,3-bis[4-(3-amino-                                                                        Pyromellitic dianhydrid                                                                    0.53                                                phenoxy)benzoyl]benzene                                                                    2.082 kg (9.55 mol)                                              5 kg (10 mol)                                                          Synthesis 6                                                                          1,3-bis[4-(3-amino-                                                                        3,3',4,4'-benzophenon-                                                                     0.51                                                phenoxy)benzoyl]benzene                                                                    tetracarboxylic                                                  4.75 kg (9.5 mol)                                                                          3,05 kg (9.52 mol)                                               Bis(4-aminophenyl)ether                                                       0.101 kg (0.5 mol)                                                     Synthesis 7                                                                          1,4-bis[4-(3-amino-                                                                        3,3',4,4'-biphenyl-                                                                        0.52                                                phenoxy)benzoyl]benzene                                                                    tetracarboxylic                                                  5.0 kg (10 mol)                                                                            dianhydride                                                                   2.81 kg (9.55 mol)                                        Synthesis 8                                                                          1,4-bis[4-(3-amino-                                                                        Pyromellitic dianhydride                                                                   0.49                                                phenoxy)benzoyl]benzene                                                                    2.07 kg (9.5 mol)                                                2.5 kg (5 mol)                                                                4,4'-bis(3-amino-                                                             phenoxy) biphenyl                                                             1.84 kg (5 mol)                                                        Synthesis 9                                                                          1,4-bis[4-(3-amino-                                                                        Bis(3,4-dicarboxy-                                                                         0.45                                                phenoxy)benzoyl]benzene                                                                    phenyl)ether dianhydride                                         4.25 kg (8.5 mol)                                                                          2.93 kg (9.45 mol)                                               Bis(4-aminophenyl)ether                                                       0.303 kg (1.5 mol)                                                     __________________________________________________________________________

EXAMPLES 107 THROUGH 131

Dry-blends of a polyimide powder obtained in any of Synthesis Examples 1through 9 with an aromatic polyamideimide powder TORLON 4203L® (AmocoChemicals Corp., USA) commercially available in varying compositionssummarized in Tables 34 through 36 were extruded, simultaneously withmelting, mixing and kneading, to form uniformly-mixed pellets.

Subsequently in thus-obtained uniformly-mixed pellet was molded in aninjection molding machine (Arburg All-Round A-20) under conditions ofmelt-mold temperature 220° C. and barrel temperature 380° to 400° C. Themolded test pieces were measured for their physical and thermalproperties.

The obtained results are given in Tables 35 through 40.

The individual Tables include minimum injection molding pressures aswell.

Data in the Tables were obtained as follows: tensile strength andelongation at break according to ASTM D-638, flexural strength andflexural modulus according to ASTM D-790, Izod impact strength accordingto D-256, glass transition temperature according to the TMAneedle-insertion method, and heat distortion temperature according toASTM D-648.

Comparative Examples 40 Through 49

With other compositions out of the scope of the fourth aspect of theinvention and in the same way as in Examples 107 through 131, moldedproducts were obtained and the measured results of their physical andthermal properties are given Tables 35 through 40.

                                      TABLE 35                                    __________________________________________________________________________                      Aromatic                                Heat                                  polyamide-                              distortion                            imide  Minimum                    Notched                                                                             tempera-                              TORLON injection                                                                           Tensile                                                                            Elongation                                                                          Flexural                                                                           Flexural                                                                           impact                                                                              ture                                                                          (°C.)               Polyimide  4203L  pressure                                                                            strength                                                                           at break                                                                            strength                                                                           modulus                                                                            strength                                                                            (18.6                      Product                                                                             Amount                                                                             Amount (kg/cm.sup.2)*                                                                      (kg/cm.sup.2)                                                                      (%)   (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg-cm/cm)                                                                          kg/cm.sup.2)        __________________________________________________________________________    Example 107                                                                          Product of                                                                          95    5     460   1250 98    1620 34500                                                                              18.3  240                 Example 108                                                                          Synthesis                                                                           85   15     465   1440 95    1770 37400                                                                              17.9  250                 Example 109                                                                          1     75   25     480   1530 93    1860 40000                                                                              17.6  258                 Example 110  50   50     500   1730 81    2050 44000                                                                              17.0  268                 Comparative  100   0     460   1100 100   1530 32400                                                                              18.3  235                 example 40                                                                    Example 111                                                                          Product of                                                                          90   10     380   1390 10    1610 35400                                                                              12.5  198                 Example 112                                                                          Synthesis                                                                           50   50     440   1710 10    2000 43600                                                                              13.0  254                 Comparative                                                                          2     100   0     380   1230 10    1450 32100                                                                              12.5  181                 example 41                                                                    __________________________________________________________________________     *Lower melt viscosity, lower minimum injection pressure. The rest is the      same.                                                                    

                                      TABLE 36                                    __________________________________________________________________________                      Aromatic                                Heat                                  polyamide-                              distortion                            imide  Minimum                    Notched                                                                             tempera-                              TORLON injection                                                                           Tensile                                                                            Elongation                                                                          Flexural                                                                           Flexural                                                                           impact                                                                              ture                                                                          (°C.)               Polyimide  4203L  pressure                                                                            strength                                                                           at break                                                                            strength                                                                           modulus                                                                            strength                                                                            (18.6                      Product                                                                             Amount                                                                             Amount (kg/cm.sup.2)*                                                                      (kg/cm.sup.2)                                                                      (%)   (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg-cm/cm)                                                                          kg/cm.sup.2)        __________________________________________________________________________    Example 113                                                                          Product of                                                                          90   10     430   1600 57    1700 28400                                                                              20.4  225                 Example 114                                                                          Synthesis                                                                           75   25     445   1670 53    1820 32400                                                                              19.8  236                 Example 115                                                                          3     50   50     485   1780 43    1970 38900                                                                              18.3  251                 Comparative  100   0     420   1550 60    1600 25500                                                                              21.0  215                 example 42                                                                    __________________________________________________________________________

                                      TABLE 37                                    __________________________________________________________________________                      Aromatic                                Heat                                  polyamide-                              distortion                            imide  Minimum                    Notched                                                                             tempera-                              TORLON injection                                                                           Tensile                                                                            Elongation                                                                          Flexural                                                                           Flexural                                                                           impact                                                                              ture                                                                          (°C.)               Polyimide  4203L  pressure                                                                            strength                                                                           at break                                                                            strength                                                                           modulus                                                                            strength                                                                            (18.6                      Product                                                                             Amount                                                                             Amount (kg/cm.sup.2)*                                                                      (kg/cm.sup.2)                                                                      (%)   (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg-cm/cm)                                                                          kg/cm.sup.2)        __________________________________________________________________________    Example 116                                                                          Product of                                                                          85   15     420   1320 34    1500 26800                                                                              11.5  202                 Example 117                                                                          Synthesis                                                                           50   50     450   1570 28    1800 37000                                                                              12.1  241                 Comparative                                                                          4     100   0     410   1150 35    1350 22000                                                                              11.0  185                 example 43                                                                    __________________________________________________________________________

                                      TABLE 38                                    __________________________________________________________________________                      Aromatic                                Heat                                  polyamide-                              distortion                            imide  Minimum                    Notched                                                                             tempera-                              TORLON injection                                                                           Tensile                                                                            Elongation                                                                          Flexural                                                                           Flexural                                                                           impact                                                                              ture                                                                          (°C.)               Polyimide  4203L  pressure                                                                            strength                                                                           at break                                                                            strength                                                                           modulus                                                                            strength                                                                            (18.6                      Product                                                                             Amount                                                                             Amount (kg/cm.sup.2)*                                                                      (kg/cm.sup.2)                                                                      (%)   (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg-cm/cm)                                                                          kg/cm.sup.2)        __________________________________________________________________________    Example 118                                                                          Product of                                                                          95    5     310   1650 68    1990 38800                                                                              16.5  230                 Example 119                                                                          Synthesis                                                                           85   15     320   1730 65    2030 41200                                                                              16.4  244                 Example 120                                                                          5     75   25     330   1790 61    2070 42800                                                                              16.4  254                 Example 121  50   50     360   1880 48    2120 45200                                                                              16.0  267                 Comparative  100   0     310   1600 70    1960 37500                                                                              16.5  220                 example 44                                                                    Comparative   0   100    610   1920 13    2150 47000                                                                              14.0  275                 example 45                                                                    __________________________________________________________________________     *Lower melt viscosity, lower minimum injection pressure. The rest is the      same.                                                                    

                                      TABLE 39                                    __________________________________________________________________________                      Aromatic                                Heat                                  polyamide-                              distortion                            imide  Minimum                    Notched                                                                             tempera-                              TORLON injection                                                                           Tensile                                                                            Elongation                                                                          Flexural                                                                           Flexural                                                                           impact                                                                              ture                                                                          (°C.)               Polyimide  4203L  pressure                                                                            strength                                                                           at break                                                                            strength                                                                           modulus                                                                            strength                                                                            (18.6                      Product                                                                             Amount                                                                             Amount (kg/cm.sup.2)*                                                                      (kg/cm.sup.2)                                                                      (%)   (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg-cm/cm)                                                                          kg/cm.sup.2)        __________________________________________________________________________    Example 122                                                                          Product of                                                                          90   10     365   1870 66    2020 40800                                                                              15.5  226                 Example 123                                                                          Synthesis                                                                           75   25     380   1900 60    2070 41800                                                                              15.5  248                 Example 124                                                                          6     50   50     405   1920 46    2130 45800                                                                              15.3  264                 Comparative  100   0     360   1850 68    1980 38000                                                                              15.5  204                 example 46                                                                    Example 125                                                                          Product of                                                                          85   15     335   1610 59    1870 41700                                                                              13.0  237                 Example 126                                                                          Synthesis                                                                           50   50     380   1830 48    2070 44700                                                                              13.8  263                 Comparative                                                                          7     100   0     320   1400 60    1700 34500                                                                              12.5  210                 example 47                                                                    __________________________________________________________________________

                                      TABLE 40                                    __________________________________________________________________________                      Aromatic                                Heat                                  polyamide-                              distortion                            imide  Minimum                    Notched                                                                             tempera-                              TORLON injection                                                                           Tensile                                                                            Elongation                                                                          Flexural                                                                           Flexural                                                                           impact                                                                              ture                                                                          (°C.)               Polyimide  4203L  pressure                                                                            strength                                                                           at break                                                                            strength                                                                           modulus                                                                            strength                                                                            (18.6                      Product                                                                             Amount                                                                             Amount (kg/cm.sup.2)*                                                                      (kg/cm.sup.2)                                                                      (%)   (kg/cm.sup.2)                                                                      (kg/cm.sup.2)                                                                      (kg-cm/cm)                                                                          kg/cm.sup.2)        __________________________________________________________________________    Example 127                                                                          Product of                                                                          90   10     425   1620 83    1870 39000                                                                              17.4  242                 Example 128                                                                          Synthesis                                                                           75   25     435   1730 80    1980 42400                                                                              17.2  254                 Example 129                                                                          8     50   50     460   1860 67    2090 45400                                                                              16.6  266                 Comparative  100   0     420   1500 85    1750 35200                                                                              17.5  231                 example 48                                                                    Example 130                                                                          Product of                                                                          85   15     360   1560 64    1730 37000                                                                              12.5  230                 Example 131                                                                          Synthesis                                                                           50   50     400   1820 53    2020 43800                                                                              13.7  260                 Comparative                                                                          9     100   0     350   1350 65    1460 30000                                                                              11.5  201                 example 49                                                                    __________________________________________________________________________

Other embodiments of the various aspects of the invention will beapparent to those skilled in the art from consideration of thespecification and practice of the aspects of the invention disclosedherein. It is intended that the specification and examples be consideredas exemplary only, with the true scope and spirit of the aspects of theinvention being indicated by the claims.

What is claimed is:
 1. A polyimide prepared by the process comprisingcarrying out condensation of 4,4'-bis(3-aminophenoxy)biphenyl of theformula: ##STR42## with pyromellitic dianhydride of the formula:##STR43## in the presence of at least one tetracarboxylic aciddianhydride of the formula: ##STR44## wherein R₂ is a tetravalent groupselected from the group consisting of an aliphatic group, an alicyclicgroup, a monocyclic aromatic group, a fused polycyclic aromatic groupand a polycyclic aromatic group combined with a member selected from thegroup consisting of a direct bond and a bridge member with the provisothat the tetracarboxylic acid dianhydride is not pyromelliticdianhydride wherein said condensation is conducted under reactionconditions sufficient to form the polyimide.
 2. The polyimide of claim 1further comprising a dicarboxylic acid anhydride.
 3. The polyimide ofclaim 2 wherein said dicarboxylic acid anhydride is present in an amountof from 0.001 to 1.0 by mole per total moles of said4,4'-bis(3-aminophenoxy)biphenyl and said diamine compound.
 4. Thepolyimide of claim 3 wherein said dicarboxylic acid anhydride isphthalic anhydride.
 5. A polyimide prepared by the process comprisingcarrying out condensation of 4,4'-bis(3-aminophenoxy)biphenyl of theformula: ##STR45## with pyromellitic dianhydride of the formula:##STR46## in the presence of at least one diamine compound in an amountof from about 1 to 100% by mole of said4,4'-bis(3-aminophenoxy)biphenyl, said at least one diamine compoundbeing selected from:(a) aminobenzylamine, phenylenediamine,diaminocyclohexane and ethylene diamine; (b) 4,4'-diaminobiphenyl,3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 4,4'-diaminobenzophenone,3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone,bis(3-aminophenyl)ether, (3-aminophenyl)(4-aminophenyl)ether,bis(3-aminophenyl)sulfide, (3-aminophenyl)(4-aminophenyl)sulfoxide,(3-aminophenyl)(4-aminophenyl)sulfoxide, bis(4-aminophenyl)sulfoxide,bis(3-aminophenyl)sulfone, (3-aminophenyl)(4-aminophenyl)sulfone,bis(4-aminophenyl)sulfone, 3,3'-diaminodiphenylmethane,3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane anddiaminonphthalene; (c) 1,3-bis(3-aminophenoxy)benzene,1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene and1,4-bis(4-aminophenoxy)benzene; (d)bis[4-(4-aminophenoxy)phenyl]methane,1,1-bis[4-(4-aminophenoxy)phenyl]ethane,1,2-bis[4-(4-aminophenoxy)phenyl]ethane,2,2-bis[4-(4-aminophenoxy)phenyl]propane,2,2-bis[4-(4-aminophenoxy)phenyl]butane,2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane,bis[4-(4aminophenoxy)phenyl]ketone,bis[4-(4-aminophenoxy)phenyl]sulfide,bis[4-(4-aminophenoxy)phenyl]sulfoxide,bis[4-(4-aminophenoxy)phenyl]sulfone and bis[4-(4-aminophenoxy)phenylether; (e) 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene,1,3-bis[4-(3-aminophenoxy)benzoyl]benzene,4,4'-bis[3-(4-aminophenoxy)benzoyl]diphenyl ether,4,4'-bis[3-(3-aminophenoxy)benzoyl]diphenyl ether,4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone,4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenyl sulfone andbis[4-{4-(4-aminophenoxy)-phenoxy}phenyl]sulfone, said condensationbeing carried out further in the presence of a tetracarboxylic aciddianhydride of the formula: ##STR47## wherein R₂ is a tetravalent groupselected from the group consisting of an aliphatic group, an alicyclicgroup, a monocyclic aromatic group, a fused polycyclic aromatic groupand a polycyclic aromatic group combined with a member selected from thegroup consisting of a direct bond and a bridge member with the provisothat the tetracarboxylic acid dianhydride is not pyromelliticdianhydride, said process further including a dicarboxylic anhydridewherein said condensation is conducted under reaction conditionssufficient to form the polyimide.
 6. The polyimide of claim 5 furthercomprising a dicarboxylic acid anhydride.
 7. The polyimide of claim 6wherein said dicarboxylic acid anhydride is present in an amount of from0.001 to 1.0 by mole per total moles of said4,4'-bis(3-aminophenoxy)biphenyl and said diamine compound.
 8. Thepolyimide of claim 7 wherein said dicarboxylic acid anhydride isphthalic anhydride.
 9. A polyimide prepared by the process comprisingcarrying out condensation of 4,4'-bis(3-aminophenoxy)biphenyl of theformula: ##STR48## with pyromellitic dianhydride of the formula:##STR49## in the presence of 4,4'-diaminodiphenyl ether in an amount ofform about 2 to 30% by mole of said 4,4'-bis(3-aminophenoxy)-biphenyl,said condensation being carried out further in the presence of atetracarboxylic acid dianhydride of the formula: ##STR50## wherein R₂ isa tetravalent group selected from the group consisting of an aliphaticgroup, an alicyclic group, a monocyclic aromatic group, a fusedpolycyclic aromatic group and a polycyclic aromatic group combined witha member selected from the group consisting of a direct bond and abridge member with the proviso that the tetracarboxylic acid dianhydrideis not pyromellitic dianhydride, said process further including adicarboxylic anhydride wherein said condensation is conducted underreaction conditions sufficient to form the polyimide.
 10. The processpolyimide claim 9 wherein said dicarboxylic acid anhydride is present inan amount of from 0.001 to 1.0 by mole per mole total moles of said4,4'-bis(3-aminophenoxy)biphenyl and said diamine compound.
 11. Thepolyimide of claim 10 wherein said dicarboxylic acid anhydride isphthalic anhydride.